1
|
Höthker S, Plato A, Grimme S, Qu ZW, Gansäuer A. Stereoconvergent Approach to the Enantioselective Construction of α-Quaternary Alcohols by Radical Epoxide Allylation. Angew Chem Int Ed Engl 2024; 63:e202405911. [PMID: 38669602 DOI: 10.1002/anie.202405911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/19/2024] [Accepted: 04/19/2024] [Indexed: 04/28/2024]
Abstract
We describe a highly stereoconvergent radical epoxide allylation towards diastereomerically and enantiomerically enriched α-quaternary alcohols in two steps from olefins. Our approach combines the stereospecifity and enantioselectivity of the Shi epoxidation with the unprecedented Ti(III)-promoted intramolecular radical group transfer allylation of epoxides. A directional isomerization step via configurationally labile radical intermediates enables the selective preparation of all-carbon quaternary stereocenters in a unique fashion.
Collapse
Affiliation(s)
- Sebastian Höthker
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Annika Plato
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstraße 4, 53115, Bonn, Germany
| | - Zheng-Wang Qu
- Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstraße 4, 53115, Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| |
Collapse
|
2
|
Cong X, Hao N, Mishra A, Zhuo Q, An K, Nishiura M, Hou Z. Regio- and Diastereoselective Annulation of α,β-Unsaturated Aldimines with Alkenes via Allylic C(sp 3)-H Activation by Rare-Earth Catalysts. J Am Chem Soc 2024; 146:10187-10198. [PMID: 38545960 DOI: 10.1021/jacs.4c02144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
The [3 + 2] or [4 + 2] annulation of α,β-unsaturated aldimines with alkenes via β'- or γ-allylic C(sp3)-H activation is, in principle, an atom-efficient route for the synthesis of five- or six-membered-ring cycloalkylamines, which are important structural motifs in numerous natural products, bioactive molecules, and pharmaceuticals. However, such a transformation has remained undeveloped to date probably due to the lack of suitable catalysts. We report herein for the first time the regio- and diastereoselective [3 + 2] and [4 + 2] annulations of α,β-unsaturated imines with alkenes via allylic C(sp3)-H activation by half-sandwich rare-earth catalysts having different metal ion sizes. The reaction of α-methyl-substituted α,β-unsaturated aldimines with alkenes by a C5Me4SiMe3-ligated scandium catalyst took place in a trans-diastereoselective [3 + 2] annulation fashion via C(sp3)-H activation at the α-methyl group (β'-position), exclusively affording alkylidene-functionalized cyclopentylamines with excellent trans-diastereoselectivity. In contrast, the reaction of β-methyl-substituted α,β-unsaturated aldimines with alkenes by a C5Me5-ligated cerium catalyst proceeded in a cis-diastereoselective [4 + 2] annulation fashion via γ-allylic C(sp3)-H activation, selectively yielding multisubstituted 2-cyclohexenylamines with excellent cis-diastereoselectivity. The mechanistic details of these transformations have been elucidated by deuterium-labeling experiments, kinetic isotope effect studies, and the isolation and transformations of key reaction intermediates. This work offers an efficient and selective protocol for the synthesis of a new family of cycloalkylamine derivatives, featuring 100% atom efficiency, high regio- and diastereoselectivity, broad substrate scope, and an unprecedented reaction mechanism.
Collapse
Affiliation(s)
- Xuefeng Cong
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Na Hao
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Aniket Mishra
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Qingde Zhuo
- Organometallic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kun An
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Masayoshi Nishiura
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Organometallic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Zhaomin Hou
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Organometallic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| |
Collapse
|
3
|
Ren H, Li T, Xing J, Li Z, Zhang Y, Yu X, Zheng J. Ti-Catalyzed Formal [2π + 2σ] Cycloadditions of Bicyclo[1.1.0]butanes with 2-Azadienes to Access Aminobicyclo[2.1.1]hexanes. Org Lett 2024; 26:1745-1750. [PMID: 38377354 DOI: 10.1021/acs.orglett.4c00421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Saturated bicyclic amines are increasingly targeted to the pharmaceutical industry as sp3-rich bioisosteres of anilines. Numerous strategies have been established for the preparation of bridgehead aminobicyclics. However, methods to assemble the bridge-amino hydrocarbon skeleton, which serves as a meta-substituted arene bioisostere, are limited. Herein, a general approach to access 2-aminobicyclo[2.1.1]hexanes (aminoBCHs) by titanium-catalyzed formal [2π + 2σ] cycloaddition of bicyclo[1.1.0]butanes and 2-azadienes was developed. Simple derivatization of aminoBCHs leads to various medicinally and agrochemically important analogues.
Collapse
Affiliation(s)
- Haosong Ren
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Tianxiang Li
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Jinping Xing
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Zhenyue Li
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Yanxia Zhang
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
| | - Xinhong Yu
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Jun Zheng
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, P. R. China
| |
Collapse
|
4
|
Schmidt J, Domenianni LI, Leuschner M, Gansäuer A, Vöhringer P. Observing the Entry Events of a Titanium-Based Photoredox Catalytic Cycle in Real Time. Angew Chem Int Ed Engl 2023; 62:e202307178. [PMID: 37335756 DOI: 10.1002/anie.202307178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/19/2023] [Accepted: 06/19/2023] [Indexed: 06/21/2023]
Abstract
Titanium-based catalysis in single electron transfer (SET) steps has evolved into a versatile approach for the synthesis of fine chemicals and first attempts have recently been made to enhance its sustainability by merging it with photo-redox (PR) catalysis. Here, we explore the photochemical principles of all-Ti-based SET-PR-catalysis, i.e. in the absence of a precious metal PR-co-catalyst. By combining time-resolved emission with ultraviolet-pump/mid-infrared-probe (UV/MIR) spectroscopy on femtosecond-to-microsecond time scales we quantify the dynamics of the critical events of entry into the catalytic cycle; namely, the singlet-triplet interconversion of the do-it-all titanocene(IV) PR-catalyst and its one-electron reduction by a sacrificial amine electron donor. The results highlight the importance of the PR-catalyst's singlet-triplet gap as a design guide for future improvements.
Collapse
Affiliation(s)
- Jonas Schmidt
- Clausius Institute for Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Wegelerstraße 12, 53115, Bonn, Germany
| | - Luis I Domenianni
- Clausius Institute for Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Wegelerstraße 12, 53115, Bonn, Germany
| | - Marcel Leuschner
- Kekulé Institute for Organic Chemistry and Biochemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Andreas Gansäuer
- Kekulé Institute for Organic Chemistry and Biochemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Peter Vöhringer
- Clausius Institute for Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Wegelerstraße 12, 53115, Bonn, Germany
| |
Collapse
|
5
|
Hilche T, Krebs T, Weißbarth H, Lang F, Schnakenburg G, Gansäuer A. Enantio- and Diastereomerically Pure Titanocenes by Dynamic Conformational Locking. Chemistry 2023; 29:e202301645. [PMID: 37283199 DOI: 10.1002/chem.202301645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/05/2023] [Accepted: 06/05/2023] [Indexed: 06/08/2023]
Abstract
The synthesis of enantiomerically pure titanocenes is limited to cases with enantiomerically pure substituents at the cyclopentadienyl ligands and to ansa-titanocenes. For the latter complexes, the use of achiral ligands requires a resolution of enantiomers and frequently also a separation of the diastereoisomers obtained after metalation. Here, we introduce a new synthetic method that relies on the use of enantiomerically pure camphorsulfonate (CSA) ligands as control elements for the absolute and relative configuration of titanocene complexes. Starting from the conformationally flexible (RC5 H4 )2 TiCl2 , the desired conformationally locked and hence enantio- and diastereomerically pure complexes (RC5 H4 )2 Ti(CSA)2 are obtained in just two steps. According to X-ray crystallography the (RC5 H4 )2 Ti fragment is essentially C2 -symmetric and nuclear magnetic resonance displays overall C2 -symmetry. We applied density functional theory methods to unravel the dynamics of the complexes and the mechanisms and selectivities of their formation.
Collapse
Affiliation(s)
- Tobias Hilche
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Tim Krebs
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Hendrik Weißbarth
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Fabian Lang
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Gregor Schnakenburg
- Institut für Anorganische Chemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| |
Collapse
|
6
|
Höthker S, Gansäuer A. Formal Anti-Markovnikov Addition of Water to Olefins by Titanocene-Catalyzed Epoxide Hydrosilylation: From Stoichiometric to Sustainable Catalytic Reactions. GLOBAL CHALLENGES (HOBOKEN, NJ) 2023; 7:2200240. [PMID: 37483422 PMCID: PMC10362118 DOI: 10.1002/gch2.202200240] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/21/2023] [Indexed: 07/25/2023]
Abstract
Here, the evolution of the titanocene-catalyzed hydrosilylation of epoxides that yields the corresponding anti-Markovnikov alcohols is summarized. The study focuses on aspects of sustainability, efficient catalyst activation, and stereoselectivity. The latest variant of the reaction employs polymethylhydrosiloxane (PMHS), a waste product of the Müller-Rochow process as terminal reductant, features an efficient catalyst activation with benzylMgBr and the use of the bench stable Cp2TiCl2 as precatalyst. The combination of olefin epoxidation and epoxide hydrosilylation provides a uniquely efficient approach to the formal anti-Markovnikov addition of H2O to olefins.
Collapse
Affiliation(s)
- Sebastian Höthker
- Kekulé‐Institut für Organische Chemie und BiochemieRheinische Friedrich‐Wilhelms‐Universität BonnGerhard‐Domagk‐Straße 153121BonnGermany
| | - Andreas Gansäuer
- Kekulé‐Institut für Organische Chemie und BiochemieRheinische Friedrich‐Wilhelms‐Universität BonnGerhard‐Domagk‐Straße 153121BonnGermany
| |
Collapse
|
7
|
Todtz SR, Schneider CW, Malakar T, Anderson C, Koska H, Zimmerman PM, Devery JJ. Controlling Catalyst Behavior in Lewis Acid-Catalyzed Carbonyl-Olefin Metathesis. J Am Chem Soc 2023; 145:13069-13080. [PMID: 37279356 PMCID: PMC10517625 DOI: 10.1021/jacs.3c01508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Lewis acid-catalyzed carbonyl-olefin metathesis has introduced a new means for revealing the behavior of Lewis acids. In particular, this reaction has led to the observation of new solution behaviors for FeCl3 that may qualitatively change how we think of Lewis acid activation. For example, catalytic metathesis reactions operate in the presence of superstoichiometric amounts of carbonyl, resulting in the formation of highly ligated (octahedral) iron geometries. These structures display reduced activity, decreasing catalyst turnover. As a result, it is necessary to steer the Fe-center away from inhibiting pathways to improve the reaction efficiency and augment yields for recalcitrant substrates. Herein, we examine the impact of the addition of TMSCl to FeCl3-catalyzed carbonyl-olefin metathesis, specifically for substrates that are prone to byproduct inhibition. Through kinetic, spectroscopic, and colligative experiments, significant deviations from the baseline metathesis reactivity are observed, including mitigation of byproduct inhibition as well as an increase in the reaction rate. Quantum chemical simulations are used to explain how TMSCl induces a change in catalyst structure that leads to these kinetic differences. Collectively, these data are consistent with the formation of a silylium catalyst, which induces the reaction through carbonyl binding. The FeCl3 activation of Si-Cl bonds to give the silylium active species is expected to have significant utility in enacting carbonyl-based transformations.
Collapse
Affiliation(s)
- Sophi R Todtz
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Cory W Schneider
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Tanmay Malakar
- Department of Chemistry, Barasat College, 10 K.N.C. Road, Barasat, Kolkata 700124, West Bengal, India
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Clare Anderson
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Heather Koska
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - James J Devery
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| |
Collapse
|
8
|
Wan X, Wang D, Huang H, Mao GJ, Deng GJ. Radical-mediated photoredox hydroarylation with thiosulfonate. Chem Commun (Camb) 2023; 59:2767-2770. [PMID: 36786060 DOI: 10.1039/d2cc05948g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Herein, we report a novel visible light-induced photocatalytic system that enables intramolecular hydroarylation of unactivated alkenes. Thiosulfonate compounds were found to be the key radical precursor that mediates the Minisci-type intramolecular cyclization reaction. Under the optimal reaction conditions, a wide range of pyridyquinazolinone and pyrroloquinazolinone products were obtained in moderate to good yields.
Collapse
Affiliation(s)
- Xiaoyuan Wan
- Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China.
| | - Dahan Wang
- Department of Food and Chemical Engineering, Shaoyang University, Shaoyang, 422100, China
| | - Huawen Huang
- Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China.
| | - Guo-Jiang Mao
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, 453007, P. R. China
| | - Guo-Jun Deng
- Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China.
| |
Collapse
|
9
|
Modular total syntheses of trans-clerodanes and sesquiterpene (hydro)quinones via tail-to-head cyclization and reductive coupling strategies. Nat Commun 2022; 13:6633. [PMID: 36333313 PMCID: PMC9636166 DOI: 10.1038/s41467-022-34404-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022] Open
Abstract
The trans-clerodanes and sesquiterpene (hydro)quinones are a growing class of natural products that exhibit a wide range of biological activities. Although they are different types of natural products, some of them feature the same trans-decalin core structure. Here, we report the total syntheses of two members of trans-clerodanes, five members of sesquiterpene (hydro)quinones as well as the proposed structure of dysidavarone D via a modular synthetic route. A bioinspired tail-to-head cyclization strategy was developed to syntheses of the trans-decalin architectures by using two diastereochemically complementary radical polyene cyclization reactions catalyzed by Ti(III) and mediated by Mn(III), respectively. The different types of side chains were introduced by challenging nickel catalyzed reductive couplings of sterically hindered alkyl halides. The synthesis of the proposed dysidavarone D proved a wrong structural assignment of the natural product.
Collapse
|
10
|
Wu X, Chang Y, Lin S. Titanium radical redox catalysis: Recent innovations in catalysts, reactions, and modes of activation. Chem 2022; 8:1805-1821. [DOI: 10.1016/j.chempr.2022.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
11
|
Hilche T, Younas SL, Gansäuer A, Streuff J. A Guide to Low‐Valent Titanocene Complexes as Tunable Single‐Electron Transfer Catalysts for Applications in Organic Chemistry. ChemCatChem 2022. [DOI: 10.1002/cctc.202200530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Tobias Hilche
- Rheinische Friedrich-Wilhelms-Universitat Bonn Kekulé-Institut für Organische Chemie und Biochemie Gerhard-Domagk-Str. 1 53121 Bonn GERMANY
| | - Sara L. Younas
- Albert-Ludwigs-Universitat Freiburg Institut für Organische Chemie Albertstr. 21 79104 Freiburg im Breisgau GERMANY
| | - Andreas Gansäuer
- Rheinische Friedrich-Wilhelms-Universitat Bonn Kekulé-Institut für Organische Chemie und Biochemie Gerhard-Domagk-Str. 1 53121 Bonn GERMANY
| | - Jan Streuff
- Uppsala Universitet Department of Chemistry - BMC Husargatan 3 752 37 Uppsala SWEDEN
| |
Collapse
|
12
|
Xie H, Wang S, Wang Y, Guo P, Shu XZ. Ti-Catalyzed Reductive Dehydroxylative Vinylation of Tertiary Alcohols. ACS Catal 2022. [DOI: 10.1021/acscatal.1c05530] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Hao Xie
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou 730000, People’s Republic of China
| | - Sheng Wang
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou 730000, People’s Republic of China
| | - Yuquan Wang
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou 730000, People’s Republic of China
| | - Peng Guo
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou 730000, People’s Republic of China
| | - Xing-Zhong Shu
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou 730000, People’s Republic of China
| |
Collapse
|
13
|
Zhou M, Wolzak LA, Li Z, de Zwart FJ, Mathew S, de Bruin B. Catalytic Synthesis of 1 H-2-Benzoxocins: Cobalt(III)-Carbene Radical Approach to 8-Membered Heterocyclic Enol Ethers. J Am Chem Soc 2021; 143:20501-20512. [PMID: 34802239 PMCID: PMC8662738 DOI: 10.1021/jacs.1c10927] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Indexed: 12/30/2022]
Abstract
The metallo-radical activation of ortho-allylcarbonyl-aryl N-arylsulfonylhydrazones with the paramagnetic cobalt(II) porphyrin catalyst [CoII(TPP)] (TPP = tetraphenylporphyrin) provides an efficient and powerful method for the synthesis of novel 8-membered heterocyclic enol ethers. The synthetic protocol is versatile and practical and enables the synthesis of a wide range of unique 1H-2-benzoxocins in high yields. The catalytic cyclization reactions proceed with excellent chemoselectivities, have a high functional group tolerance, and provide several opportunities for the synthesis of new bioactive compounds. The reactions are shown to proceed via cobalt(III)-carbene radical intermediates, which are involved in intramolecular hydrogen transfer (HAT) from the allylic position to the carbene radical, followed by a near-barrierless radical rebound step in the coordination sphere of cobalt. The proposed mechanism is supported by experimental observations, density functional theory (DFT) calculations, and spin trapping experiments.
Collapse
Affiliation(s)
- Minghui Zhou
- Homogeneous,
Supramolecular and Bio-Inspired Catalysis (HomKat) group, Van ‘t
Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Lukas A. Wolzak
- Homogeneous,
Supramolecular and Bio-Inspired Catalysis (HomKat) group, Van ‘t
Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Zirui Li
- Department
of Bioorganic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333
CC Leiden, The Netherlands
| | - Felix J. de Zwart
- Homogeneous,
Supramolecular and Bio-Inspired Catalysis (HomKat) group, Van ‘t
Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Simon Mathew
- Homogeneous,
Supramolecular and Bio-Inspired Catalysis (HomKat) group, Van ‘t
Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Bas de Bruin
- Homogeneous,
Supramolecular and Bio-Inspired Catalysis (HomKat) group, Van ‘t
Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| |
Collapse
|
14
|
Affiliation(s)
- Sandeepan Maity
- Department of Applied Sciences and Humanities Invertis University Bareilly Uttar Pradesh 243123 India
| |
Collapse
|
15
|
Younas SL, Streuff J. Kinetic Analysis Uncovers Hidden Autocatalysis and Inhibition Pathways in Titanium(III)-Catalyzed Ketone-Nitrile Couplings. ACS Catal 2021. [DOI: 10.1021/acscatal.1c02870] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Sara L. Younas
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - Jan Streuff
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
- Department of Chemistry—BMC, Uppsala University, Husargatan 3, 75237 Uppsala, Sweden
| |
Collapse
|
16
|
Zhao B, Rogge T, Ackermann L, Shi Z. Metal-catalysed C-Het (F, O, S, N) and C-C bond arylation. Chem Soc Rev 2021; 50:8903-8953. [PMID: 34190223 DOI: 10.1039/c9cs00571d] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The formation of C-aryl bonds has been the focus of intensive research over the last decades for the construction of complex molecules from simple, readily available feedstocks. Traditionally, these strategies involve the coupling of organohalides (I, Br, Cl) with organometallic reagents (Mg, Zn, B, Si, Sn,…) such as Kumada-Corriu, Negishi, Suzuki-Miyaura, Hiyama and Sonogashira cross-couplings. More recently, alternative methods have provided access to these products by reactions with less reactive C-Het (F, O, S, N) and C-C bonds. Compared to traditional methods, the direct cleavage and arylation of these chemical bonds, the essential link in accessible feedstocks, has become increasingly important from the viewpoint of step-economy and functional-group compatibility. This comprehensive review aims to outline the development and advances of this topic, which was organized into (1) C-F bond arylation, (2) C-O bond arylation, (3) C-S bond arylation, (4) C-N bond arylation, and (5) C-C bond arylation. Substantial attention has been paid to the strategies and mechanistic investigations. We hope that this review can trigger chemists to discover more efficient methodologies to access arylation products by cleavage of these C-Het and C-C bonds.
Collapse
Affiliation(s)
- Binlin Zhao
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
| | | | | | | |
Collapse
|
17
|
Zhang Z, Stückrath JB, Grimme S, Gansäuer A. Titanocene‐Catalyzed [2+2] Cycloaddition of Bisenones and Comparison with Photoredox Catalysis and Established Methods. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Zhenhua Zhang
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard-Domagk-Strasse 1 53121 Bonn Germany
| | - Julius B. Stückrath
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie Universität Bonn Beringstrasse 4 53115 Bonn Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie Universität Bonn Beringstrasse 4 53115 Bonn Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard-Domagk-Strasse 1 53121 Bonn Germany
| |
Collapse
|
18
|
Zhang Z, Stückrath JB, Grimme S, Gansäuer A. Titanocene-Catalyzed [2+2] Cycloaddition of Bisenones and Comparison with Photoredox Catalysis and Established Methods. Angew Chem Int Ed Engl 2021; 60:14339-14344. [PMID: 33871126 PMCID: PMC8251790 DOI: 10.1002/anie.202102739] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Indexed: 12/17/2022]
Abstract
Cp2 Ti(TFA) is a broadly applicable catalyst for the [2+2] cycloaddition of bisenones by inner-sphere electron transfer. The attractiveness of this mechanism is shown by comparison with outer-sphere ET methods. DFT calculations show that the reaction proceeds through a unique unfavorable 5-exo (the rate-determining step) and a favorable 4-exo cyclization.
Collapse
Affiliation(s)
- Zhenhua Zhang
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Strasse 153121BonnGermany
| | - Julius B. Stückrath
- Mulliken Center for Theoretical ChemistryInstitut für Physikalische und Theoretische ChemieUniversität BonnBeringstrasse 453115BonnGermany
| | - Stefan Grimme
- Mulliken Center for Theoretical ChemistryInstitut für Physikalische und Theoretische ChemieUniversität BonnBeringstrasse 453115BonnGermany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Strasse 153121BonnGermany
| |
Collapse
|
19
|
Kern C, Selau J, Streuff J. A Titanium-Catalyzed Reductive α-Desulfonylation. Chemistry 2021; 27:6178-6182. [PMID: 33539578 PMCID: PMC8048938 DOI: 10.1002/chem.202005400] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/09/2021] [Indexed: 12/14/2022]
Abstract
A titanium(III)-catalyzed desulfonylation gives access to functionalized alkyl nitrile building blocks from α-sulfonyl nitriles, circumventing traditional base-mediated α-alkylation conditions and strong single electron donors. The reaction tolerates numerous functional groups including free alcohols, esters, amides, and it can be applied also to the α-desulfonylation of ketones. In addition, a one-pot desulfonylative alkylation is demonstrated. Preliminary mechanistic studies indicate a catalyst-dependent mechanism involving a homolytic C-S cleavage.
Collapse
Affiliation(s)
- Christoph Kern
- Institut für Organische ChemieAlbert-Ludwigs-Universität FreiburgAlbertstr. 2179104Freiburg im BreisgauGermany
| | - Jan Selau
- Institut für Organische ChemieAlbert-Ludwigs-Universität FreiburgAlbertstr. 2179104Freiburg im BreisgauGermany
| | - Jan Streuff
- Institut für Organische ChemieAlbert-Ludwigs-Universität FreiburgAlbertstr. 2179104Freiburg im BreisgauGermany
| |
Collapse
|
20
|
Liu Z, Zhong S, Ji X, Deng GJ, Huang H. Hydroarylation of Activated Alkenes Enabled by Proton-Coupled Electron Transfer. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00649] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Zhaosheng Liu
- Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Shuai Zhong
- Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Xiaochen Ji
- Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Guo-Jun Deng
- Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Huawen Huang
- Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
| |
Collapse
|
21
|
Hilche T, Reinsberg PH, Klare S, Liedtke T, Schäfer L, Gansäuer A. Design Platform for Sustainable Catalysis with Radicals: Electrochemical Activation of Cp 2 TiCl 2 for Catalysis Unveiled. Chemistry 2021; 27:4903-4912. [PMID: 33085978 PMCID: PMC7986168 DOI: 10.1002/chem.202004519] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Indexed: 12/17/2022]
Abstract
The combination of synthesis, rotating ring-disk electrode (RRDE) and cyclic voltammetry (CV) measurements, and computational investigations with the aid of DFT methods shows how a thiourea, a squaramide, and a bissulfonamide as additives affect the Eq Cr equilibrium of Cp2 TiCl2 . We have, for the first time, provided quantitative data for the Eq Cr equilibrium and have determined the stoichiometry of adduct formation of [Cp2 Ti(III)Cl2 ]- , [Cp2 Ti(III)Cl] and [Cp2 Ti(IV)Cl2 ] and the additives. By studying the structures of the complexes formed by DFT methods, we have established the Gibbs energies and enthalpies of complex formation as well as the adduct structures. The results not only demonstrate the correctness of our use of the Eq Cr equilibrium as predictor for sustainable catalysis. They are also a design platform for the development of novel additives in particular for enantioselective catalysis.
Collapse
Affiliation(s)
- Tobias Hilche
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
| | - Philip H. Reinsberg
- Institut für Physikalische und Theoretische Chemie, Universität BonnRömerstraße 16453117BonnGermany
| | - Sven Klare
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
| | - Theresa Liedtke
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
| | - Luise Schäfer
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard-Domagk-Straße 153121BonnGermany
| |
Collapse
|
22
|
Funk P, Richrath RB, Bohle F, Grimme S, Gansäuer A. Oxidation Under Reductive Conditions: From Benzylic Ethers to Acetals with Perfect Atom-Economy by Titanocene(III) Catalysis. Angew Chem Int Ed Engl 2021; 60:5482-5488. [PMID: 33245820 PMCID: PMC7986230 DOI: 10.1002/anie.202013561] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Indexed: 12/19/2022]
Abstract
Described here is a titanocene-catalyzed reaction for the synthesis of acetals and hemiaminals from benzylic ethers and benzylic amines, respectively, with pendant epoxides. The reaction proceeds by catalysis in single-electron steps. The oxidative addition comprises an epoxide opening. An H-atom transfer, to generate a benzylic radical, serves as a radical translocation step, and an organometallic oxygen rebound as a reductive elimination. The reaction mechanism was studied by high-level dispersion corrected hybrid functional DFT with implicit solvation. The low-energy conformational space was searched by the efficient CREST program. The stereoselectivity was deduced from the lowest lying benzylic radical structures and their conformations are controlled by hyperconjugative interactions and steric interactions between the titanocene catalyst and the aryl groups of the substrate. An interesting mechanistic aspect is that the oxidation of the benzylic center occurs under reducing conditions.
Collapse
Affiliation(s)
- Pierre Funk
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Str. 153121BonnGermany
| | - Ruben B. Richrath
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Str. 153121BonnGermany
| | - Fabian Bohle
- Mulliken Center for Theoretical ChemistryInstitut für Physikalische und Theoretische ChemieUniversität BonnBeringstraße 453115BonnGermany
| | - Stefan Grimme
- Mulliken Center for Theoretical ChemistryInstitut für Physikalische und Theoretische ChemieUniversität BonnBeringstraße 453115BonnGermany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Str. 153121BonnGermany
| |
Collapse
|
23
|
Nugent WA, RajanBabu TV. Four Mechanistic Mysteries: The Benefits of Writing a Critical Review. Angew Chem Int Ed Engl 2021; 60:2194-2201. [PMID: 33270349 PMCID: PMC7994932 DOI: 10.1002/anie.202011838] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Indexed: 11/07/2022]
Abstract
While writing a comprehensive review on the reactions of epoxides with titanium(III) reagents, we encountered a series of mechanistic puzzles. Using clues from the literature, many of which were not available at the time that the mysteries emerged, it was possible to demystify a number of these conundrums. We discuss four examples, which we believe will significantly change the way in which titanium(III) chemistry is practiced. Our experience underscores the importance of comprehensive and critical reviews in chemistry and the truism that the authors are prime beneficiaries of the review process.
Collapse
Affiliation(s)
- William A Nugent
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Street, Columbus, OH, 43210, USA
| | - T V RajanBabu
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Street, Columbus, OH, 43210, USA
| |
Collapse
|
24
|
Funk P, Richrath RB, Bohle F, Grimme S, Gansäuer A. Oxidation Under Reductive Conditions: From Benzylic Ethers to Acetals with Perfect Atom‐Economy by Titanocene(III) Catalysis. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202013561] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Pierre Funk
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Str. 1 53121 Bonn Germany
| | - Ruben B. Richrath
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Str. 1 53121 Bonn Germany
| | - Fabian Bohle
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie Universität Bonn Beringstraße 4 53115 Bonn Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie Universität Bonn Beringstraße 4 53115 Bonn Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Str. 1 53121 Bonn Germany
| |
Collapse
|
25
|
Nugent WA, RajanBabu TV. Four Mechanistic Mysteries: The Benefits of Writing a Critical Review. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011838] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- William A. Nugent
- Department of Chemistry and Biochemistry The Ohio State University 100 West 18th Street Columbus OH 43210 USA
| | - T. V. RajanBabu
- Department of Chemistry and Biochemistry The Ohio State University 100 West 18th Street Columbus OH 43210 USA
| |
Collapse
|
26
|
Hardy M, Lützen A. Better Together: Functional Heterobimetallic Macrocyclic and Cage-like Assemblies. Chemistry 2020; 26:13332-13346. [PMID: 32297380 PMCID: PMC7693062 DOI: 10.1002/chem.202001602] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/14/2020] [Indexed: 12/18/2022]
Abstract
Metallosupramolecular chemistry has attracted the interest of generations of researches due to the versatile properties and functionalities of oligonuclear coordination complexes. Quite a number of different discrete cages were investigated, mostly consisting of only one type of ligand and one type of metal cation. Looking for ever more complex structures, heterobimetallic complexes became more and more attractive, as they give access to new structural motifs and functions. In the last years substantial success has been made in the design and synthesis of cages consisting of more than one type of metal cations, and a rapidly growing number of functional materials has appeared in the literature. This Minireview describes recent developments in the field of discrete heterometallic macrocycles and cages focusing on functional materials that have been used as host‐systems or as magnetic, photo‐active, redox‐active, and even catalytically active materials.
Collapse
Affiliation(s)
- Matthias Hardy
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str.1, 53111, Bonn, Germany
| | - Arne Lützen
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str.1, 53111, Bonn, Germany
| |
Collapse
|
27
|
Manßen M, Schafer LL. Titanium catalysis for the synthesis of fine chemicals – development and trends. Chem Soc Rev 2020; 49:6947-6994. [DOI: 10.1039/d0cs00229a] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Atlas as a Titan(ium) is holding the earth-abundant chemistry world. Titanium is the second most abundant transition metal, is a key player in important industrial processes (e.g. polyethylene) and shows much promise for diverse applications in the future.
Collapse
Affiliation(s)
- Manfred Manßen
- The Department of Chemistry
- The University of British Columbia
- Vancouver
- Canada
| | - Laurel L. Schafer
- The Department of Chemistry
- The University of British Columbia
- Vancouver
- Canada
| |
Collapse
|
28
|
Tian S, Lv S, Jia X, Ma L, Li B, Zhang G, Gao W, Wei Y, Chen J. CV‐driven Optimization: Cobalt‐Catalyzed Electrochemical Expedient Oxychlorination of Alkenes via ORR. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201901260] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Siyu Tian
- Shandong Provincial Key Laboratory of Molecular EngineeringState Key Laboratory of Biobased Material and Green PapermakingSchool of Chemistry and Pharmaceutical Engineering Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 People's Republic of China
| | - Shide Lv
- Shandong Provincial Key Laboratory of Molecular EngineeringState Key Laboratory of Biobased Material and Green PapermakingSchool of Chemistry and Pharmaceutical Engineering Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 People's Republic of China
| | - Xiaofei Jia
- Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOECollege of Chemistry and Molecular Engineering. Qingdao University of Science and Technology Qingdao 266042 People's Republic of China
| | - Li Ma
- Shandong Provincial Key Laboratory of Molecular EngineeringState Key Laboratory of Biobased Material and Green PapermakingSchool of Chemistry and Pharmaceutical Engineering Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 People's Republic of China
| | - Baoying Li
- Shandong Provincial Key Laboratory of Molecular EngineeringState Key Laboratory of Biobased Material and Green PapermakingSchool of Chemistry and Pharmaceutical Engineering Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 People's Republic of China
| | - Guofeng Zhang
- Shandong Provincial Key Laboratory of Molecular EngineeringState Key Laboratory of Biobased Material and Green PapermakingSchool of Chemistry and Pharmaceutical Engineering Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 People's Republic of China
| | - Wei Gao
- Shandong Provincial Key Laboratory of Molecular EngineeringState Key Laboratory of Biobased Material and Green PapermakingSchool of Chemistry and Pharmaceutical Engineering Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 People's Republic of China
| | - Yingqin Wei
- Shandong Provincial Key Laboratory of Molecular EngineeringState Key Laboratory of Biobased Material and Green PapermakingSchool of Chemistry and Pharmaceutical Engineering Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 People's Republic of China
| | - Jianbin Chen
- Shandong Provincial Key Laboratory of Molecular EngineeringState Key Laboratory of Biobased Material and Green PapermakingSchool of Chemistry and Pharmaceutical Engineering Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 People's Republic of China
| |
Collapse
|
29
|
Abstract
New catalytic strategies that leverage single-electron redox events have provided chemists with useful tools for solving synthetic problems. In this context, Ti offers opportunities that are complementary to late transition metals for reaction discovery. Following foundational work on epoxide reductive functionalization, recent methodological advances have significantly expanded the repertoire of Ti radical chemistry. This Synopsis summarizes recent developments in the burgeoning area of Ti radical catalysis with a focus on innovative catalytic strategies such as radical redox-relay and dual catalysis.
Collapse
Affiliation(s)
- Terry McCallum
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| | - Xiangyu Wu
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| | - Song Lin
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| |
Collapse
|
30
|
Mühlhaus F, Weißbarth H, Dahmen T, Schnakenburg G, Gansäuer A. Merging Regiodivergent Catalysis with Atom-Economical Radical Arylation. Angew Chem Int Ed Engl 2019; 58:14208-14212. [PMID: 31394024 PMCID: PMC6852184 DOI: 10.1002/anie.201908860] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Indexed: 12/11/2022]
Abstract
A titanocene-catalyzed regiodivergent radical arylation is described that allows access to either enantiomerically pure tetrahydroquinolines or indolines from a common starting material. The regioselectivity of epoxide opening that results in the high selectivity of heterocycle formation is controlled by two factors, the absolute configuration of the enantiopure ligands of the (C5 H4 R)2 TiX2 catalyst and the inorganic ligand X (X=Cl, OTs). The overall reaction is atom-economical and constitutes a radical Friedel-Crafts alkylation.
Collapse
Affiliation(s)
- Felix Mühlhaus
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
| | - Hendrik Weißbarth
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
| | - Tobias Dahmen
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
| | - Gregor Schnakenburg
- Institut für Anorganische ChemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und BiochemieUniversität BonnGerhard Domagk-Straße 153121BonnGermany
| |
Collapse
|
31
|
Mühlhaus F, Weißbarth H, Dahmen T, Schnakenburg G, Gansäuer A. Merging Regiodivergent Catalysis with Atom‐Economical Radical Arylation. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201908860] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Felix Mühlhaus
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Hendrik Weißbarth
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Tobias Dahmen
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Gregor Schnakenburg
- Institut für Anorganische Chemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie Universität Bonn Gerhard Domagk-Straße 1 53121 Bonn Germany
| |
Collapse
|
32
|
Liedtke T, Hilche T, Klare S, Gansäuer A. Condition Screening for Sustainable Catalysis in Single-Electron Steps by Cyclic Voltammetry: Additives and Solvents. CHEMSUSCHEM 2019; 12:3166-3171. [PMID: 30779429 DOI: 10.1002/cssc.201900344] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 02/18/2019] [Indexed: 06/09/2023]
Abstract
Cyclic voltammetry-based screening method for Cp2 TiX-catalyzed reactions is extended to the screening of solvents other than tetrahydrofuran for bulk electrolysis of the catalyst and radical arylation. It was found that CH3 CN can be used as a solvent for both processes without additives. Furthermore, in tetrahydrofuran, squaramide L2 is more efficient than the previously reported supramolecular halide binder, Schreiner's thiourea L1. The results extend the usefulness of the proposed time and resource-efficient screening method for designing catalysis reactions in single-electron steps.
Collapse
Affiliation(s)
- Theresa Liedtke
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Tobias Hilche
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Sven Klare
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| |
Collapse
|
33
|
Jaraíz M, Rubio JE, Enríquez L, Pinacho R, López-Pérez JL, Lesarri A. An Efficient Microkinetic Modeling Protocol: Start with Only the Dominant Mechanisms, Adjust All Parameters, and Build the Complete Model Incrementally. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00522] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Martín Jaraíz
- Department of Electronics, ETSIT, University of Valladolid, Paseo de Belén 15, Valladolid 47011, Spain
- IU CINQUIMA, University of Valladolid, Paseo de Belén 7, 47011 Valladolid, Spain
| | - José E. Rubio
- Department of Electronics, ETSIT, University of Valladolid, Paseo de Belén 15, Valladolid 47011, Spain
| | - Lourdes Enríquez
- Department of Electronics, ETSIT, University of Valladolid, Paseo de Belén 15, Valladolid 47011, Spain
| | - Ruth Pinacho
- Department of Electronics, ETSIT, University of Valladolid, Paseo de Belén 15, Valladolid 47011, Spain
| | - José L. López-Pérez
- Department of Pharmacology, Faculty of Medicine, University of Panama, Panama City, Panama
- Department of Pharmaceutical Sciences - IBSAL-CIETUS, University of Salamanca, Avda. Campo
Charro s/n, Salamanca 37071, Spain
| | - Alberto Lesarri
- Department of Physical Chemistry and Inorganic Chemistry, Faculty of Sciences, University of Valladolid, Paseo Belén 7, Valladolid 47011, Spain
| |
Collapse
|
34
|
Lankelma M, Olivares AM, de Bruin B. [Co(TPP)]-Catalyzed Formation of Substituted Piperidines. Chemistry 2019; 25:5658-5663. [PMID: 30844097 PMCID: PMC6563703 DOI: 10.1002/chem.201900587] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Indexed: 01/12/2023]
Abstract
Radical cyclization via cobalt(III)-carbene radical intermediates is a powerful method for the synthesis of (hetero)cyclic structures. Building on the recently reported synthesis of five-membered N-heterocyclic pyrrolidines catalyzed by CoII porphyrins, the [Co(TPP)]-catalyzed formation of useful six-membered N-heterocyclic piperidines directly from linear aldehydes is presented herein. The piperidines were obtained in overall high yields, with linear alkenes being formed as side products in small amounts. A DFT study was performed to gain a deeper mechanistic understanding of the cobalt(II)-porphyrin-catalyzed formation of pyrrolidines, piperidines, and linear alkenes. The calculations showed that the alkenes are unlikely to be formed through an expected 1,2-hydrogen-atom transfer to the carbene carbon. Instead, the calculations were consistent with a pathway involving benzyl-radical formation followed by radical-rebound ring closure to form the piperidines. Competitive 1,5-hydrogen-atom transfer from the β-position to the benzyl radical explained the formation of linear alkenes as side products.
Collapse
Affiliation(s)
- Marianne Lankelma
- Van 't Hoff Institute for Molecular Sciences (HIMS)Homogeneous, Supramolecular & Bio-Inspired CatalysisUniversity of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands
| | - Astrid M. Olivares
- Department of ChemistryUniversity of Rochester404 Hutchison HallRochesterNY14627-0216USA
| | - Bas de Bruin
- Van 't Hoff Institute for Molecular Sciences (HIMS)Homogeneous, Supramolecular & Bio-Inspired CatalysisUniversity of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands
| |
Collapse
|
35
|
Zhang Z, Richrath RB, Gansäuer A. Merging Catalysis in Single Electron Steps with Photoredox Catalysis—Efficient and Sustainable Radical Chemistry. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00787] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Zhenhua Zhang
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Ruben B. Richrath
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| |
Collapse
|
36
|
Leijendekker LH, Weweler J, Leuther TM, Kratzert D, Streuff J. Development, Scope, and Applications of Titanium(III)-Catalyzed Cyclizations to Aminated N-Heterocycles. Chemistry 2019; 25:3382-3390. [PMID: 30615817 DOI: 10.1002/chem.201805909] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 01/30/2023]
Affiliation(s)
- Leonardus H. Leijendekker
- Institut für Organische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstr. 21 79104 Freiburg im Breisgau Germany
| | - Jens Weweler
- Institut für Organische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstr. 21 79104 Freiburg im Breisgau Germany
| | - Tobias M. Leuther
- Institut für Organische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstr. 21 79104 Freiburg im Breisgau Germany
| | - Daniel Kratzert
- Institut für Anorganische und Analytische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstr. 21 79104 Freiburg im Breisgau Germany
| | - Jan Streuff
- Institut für Organische Chemie; Albert-Ludwigs-Universität Freiburg; Albertstr. 21 79104 Freiburg im Breisgau Germany
| |
Collapse
|
37
|
Maity S, Flowers RA. Mechanistic Study and Development of Catalytic Reactions of Sm(II). J Am Chem Soc 2019; 141:3207-3216. [DOI: 10.1021/jacs.8b13119] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Sandeepan Maity
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Robert A. Flowers
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| |
Collapse
|
38
|
Huang HM, Garduño-Castro MH, Morrill C, Procter DJ. Catalytic cascade reactions by radical relay. Chem Soc Rev 2019; 48:4626-4638. [DOI: 10.1039/c8cs00947c] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Catalytic radical relays are an attractive tool for the rapid construction of complex molecular architectures.
Collapse
|
39
|
Gordon J, Hildebrandt S, Dewese KR, Klare S, Gansäuer A, RajanBabu TV, Nugent WA. Demystifying Cp 2Ti(H)Cl and its Enigmatic Role in the Reactions of Epoxides with Cp 2TiCl. Organometallics 2018; 37:4801-4809. [PMID: 30733623 DOI: 10.1021/acs.organomet.8b00793] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of Cp2Ti(H)Cl in the reactions of Cp2TiCl with trisubstituted epoxides has been investigated in a combined experimental and computational study. Although Cp2Ti(H)Cl has generally been regarded as a robust species, its decomposition to Cp2TiCl and molecular hydrogen was found to be exothermic (ΔG = -11 kcal/mol when the effects of THF solvation are considered). In laboratory studies, Cp2Ti(H)Cl was generated using the reaction of 1,2-epoxy-1-methylcyclohexane with Cp2TiCl as a model. Rapid evolution of hydrogen gas was demonstrated, indicating that Cp2Ti(H)Cl is indeed a thermally unstable molecule, which undergoes intermolecular reductive elimination of hydrogen under the reaction conditions. The stoichiometry of the reaction (Cp2TiCl:epoxide = 1:1) and the quantity of hydrogen produced (1 mole per 2 moles of epoxide) is consistent with this assertion. The diminished yield of allylic alcohol from these reactions under the conditions of protic versus aprotic catalysis can be understood in terms of the predominant titanium(III) present in solution. Under the conditions of protic catalysis, Cp2TiCl complexes with collidine hydrochloride and the titanium(III) center is less available for "cross-disproportionation" with carbon-centered radicals; this leads to by-products from radical capture by hydrogen atom transfer, resulting in a saturated alcohol.
Collapse
Affiliation(s)
- Jonathan Gordon
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA
| | - Sven Hildebrandt
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Kendra R Dewese
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA
| | - Sven Klare
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - T V RajanBabu
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA
| | - William A Nugent
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA
| |
Collapse
|
40
|
Wu X, Hao W, Ye KY, Jiang B, Pombar G, Song Z, Lin S. Ti-Catalyzed Radical Alkylation of Secondary and Tertiary Alkyl Chlorides Using Michael Acceptors. J Am Chem Soc 2018; 140:14836-14843. [PMID: 30303379 PMCID: PMC6530901 DOI: 10.1021/jacs.8b08605] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alkyl chlorides are common functional groups in synthetic organic chemistry. However, the engagement of unactivated alkyl chlorides, especially tertiary alkyl chlorides, in transition-metal-catalyzed C-C bond formation remains challenging. Herein, we describe the development of a TiIII-catalyzed radical addition of 2° and 3° alkyl chlorides to electron-deficient alkenes. Mechanistic data are consistent with inner-sphere activation of the C-Cl bond featuring TiIII-mediated Cl atom abstraction. Evidence suggests that the active TiIII catalyst is generated from the TiIV precursor in a Lewis-acid-assisted electron transfer process.
Collapse
Affiliation(s)
- Xiangyu Wu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | | | - Ke-Yin Ye
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Binyang Jiang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Gisselle Pombar
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Zhidong Song
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Song Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| |
Collapse
|
41
|
Karns AS, Goswami M, de Bruin B. Catalytic Synthesis of Indolines by Hydrogen Atom Transfer to Cobalt(III)-Carbene Radicals. Chemistry 2018; 24:5253-5258. [PMID: 29143995 PMCID: PMC5915749 DOI: 10.1002/chem.201704626] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Indexed: 11/28/2022]
Abstract
We report a new method for the synthesis of indolines from o-aminobenzylidine N-tosylhydrazones proceeding through a cobalt(III)-carbene radical intermediate. This methodology employs the use of inexpensive commercially available reagents and allows for the transformation of easily derivatized benzaldehyde-derived precursors to functionalized indoline products. This transformation takes advantage of the known propensity of radicals to undergo rapid intramolecular 1,5-hydrogen atom transfer (1,5-HAT) to form more stabilized radical intermediates. Computational investigations using density functional theory identify remarkably low barriers for 1,5-HAT and subsequent radical rebound displacement, providing support for the proposed mechanism. We explore the effect of a variety of nitrogen substituents, and highlight the importance of adequate resonance stabilization of radical intermediates to the success of the transformation. Furthermore, we evaluate the steric and electronic effects of substituents on the aniline ring. This transformation is the first reported example of the synthesis of nitrogen-containing heterocycles from cobalt(III)-carbene radical precursors.
Collapse
Affiliation(s)
- Alexander S. Karns
- Department of ChemistryUniversity of California, Irvine1102 Natural Sciences IIIrvineCA92697-2025USA
| | - Monalisa Goswami
- Van't Hoff Institute for Molecular Sciences (HIMS)Homogeneous and Supramolecular Catalysis groupUniversity of AmsterdamScience Park 9041098XHAmsterdamThe Netherlands
| | - Bas de Bruin
- Van't Hoff Institute for Molecular Sciences (HIMS)Homogeneous and Supramolecular Catalysis groupUniversity of AmsterdamScience Park 9041098XHAmsterdamThe Netherlands
| |
Collapse
|
42
|
Streuff J, Himmel D, Younas SL. Understanding titanium-catalysed radical-radical reactions: a DFT study unravels the complex kinetics of ketone-nitrile couplings. Dalton Trans 2018; 47:5072-5082. [PMID: 29561012 DOI: 10.1039/c8dt00643a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The computational investigation of a titanium-catalysed reductive radical-radical coupling is reported. The results match the conclusions from an earlier experimental study and enable a further interpretation of the previously observed complex reaction kinetics. Furthermore, the interplay between neutral and cationic reaction pathways in titanium(iii)-catalysed reactions is investigated for the first time. The results show that hydrochloride additives and reaction byproducts play an important role in the respective equilibria. A full reaction profile is assembled and the computed activation barrier is found to be in reasonable agreement with the experiment. The conclusions are of fundamental importance to the field of low-valent titanium catalysis and the understanding of related catalytic radical-radical coupling reactions.
Collapse
Affiliation(s)
- Jan Streuff
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany.
| | - Daniel Himmel
- Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - Sara L Younas
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany.
| |
Collapse
|
43
|
Liedtke T, Spannring P, Riccardi L, Gansäuer A. Mechanism-Based Condition Screening for Sustainable Catalysis in Single-Electron Steps by Cyclic Voltammetry. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800731] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Theresa Liedtke
- Kekulé-Institut für Organische Chemie und Biochemie; Universität Bonn; Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Peter Spannring
- Kekulé-Institut für Organische Chemie und Biochemie; Universität Bonn; Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Ludovico Riccardi
- Kekulé-Institut für Organische Chemie und Biochemie; Universität Bonn; Gerhard Domagk-Straße 1 53121 Bonn Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie; Universität Bonn; Gerhard Domagk-Straße 1 53121 Bonn Germany
| |
Collapse
|
44
|
Liedtke T, Spannring P, Riccardi L, Gansäuer A. Mechanism-Based Condition Screening for Sustainable Catalysis in Single-Electron Steps by Cyclic Voltammetry. Angew Chem Int Ed Engl 2018; 57:5006-5010. [PMID: 29488673 DOI: 10.1002/anie.201800731] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 02/22/2018] [Indexed: 12/16/2022]
Abstract
A cyclic-voltammetry-based screening method for Cp2 TiX-catalyzed reactions is introduced. Our mechanism-based approach enables the study of the influence of various additives on the electrochemically generated active catalyst Cp2 TiX, which is in equilibrium with catalytically inactive [Cp2 TiX2 ]- . Thioureas and ureas are most efficient in the generation of Cp2 TiX in THF. Knowing the precise position of the equilibrium between Cp2 TiX and [Cp2 TiX2 ]- allowed us to identify reaction conditions for the bulk electrolysis of Cp2 TiX2 complexes and for Cp2 TiX-catayzed radical arylations without having to carry out the reactions. Our time- and resource-efficient approach is of general interest for the design of catalytic reactions that proceed in single-electron steps.
Collapse
Affiliation(s)
- Theresa Liedtke
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Straße 1, 53121, Bonn, Germany
| | - Peter Spannring
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Straße 1, 53121, Bonn, Germany
| | - Ludovico Riccardi
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Straße 1, 53121, Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Straße 1, 53121, Bonn, Germany
| |
Collapse
|
45
|
Richrath RB, Olyschläger T, Hildebrandt S, Enny DG, Fianu GD, Flowers RA, Gansäuer A. Cp 2 TiX Complexes for Sustainable Catalysis in Single-Electron Steps. Chemistry 2018; 24:6371-6379. [PMID: 29327511 DOI: 10.1002/chem.201705707] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Indexed: 12/18/2022]
Abstract
We present a combined electrochemical, kinetic, and synthetic study with a novel and easily accessible class of titanocene catalysts for catalysis in single-electron steps. The tailoring of the electronic properties of our Cp2 TiX-catalysts that are prepared in situ from readily available Cp2 TiX2 is achieved by varying the anionic ligand X. Of the complexes investigated, Cp2 TiOMs proved to be either equal or substantially superior to the best catalysts developed earlier. The kinetic and thermodynamic properties pertinent to catalysis have been determined. They allow a mechanistic understanding of the subtle interplay of properties required for an efficient oxidative addition and reduction. Therefore, our study highlights that efficient catalysts do not require the elaborate covalent modification of the cyclopentadienyl ligands.
Collapse
Affiliation(s)
- Ruben B Richrath
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Str. 1, 53121, Bonn, Germany
| | - Theresa Olyschläger
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Str. 1, 53121, Bonn, Germany
| | - Sven Hildebrandt
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Str. 1, 53121, Bonn, Germany
| | - Daniel G Enny
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Godfred D Fianu
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Robert A Flowers
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk-Str. 1, 53121, Bonn, Germany
| |
Collapse
|
46
|
Hao W, Harenberg JH, Wu X, MacMillan SN, Lin S. Diastereo- and Enantioselective Formal [3 + 2] Cycloaddition of Cyclopropyl Ketones and Alkenes via Ti-Catalyzed Radical Redox Relay. J Am Chem Soc 2018; 140:3514-3517. [DOI: 10.1021/jacs.7b13710] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Wei Hao
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Johannes H. Harenberg
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Department Chemie, Ludwig-Maximilians-Universität München, Munich, 81377, Germany
| | - Xiangyu Wu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Samantha N. MacMillan
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Song Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Atkinson Center for a Sustainable Future, Cornell University, Ithaca, New York 14853, United States
| |
Collapse
|
47
|
van Leest NP, Epping RF, van Vliet KM, Lankelma M, van den Heuvel EJ, Heijtbrink N, Broersen R, de Bruin B. Single-Electron Elementary Steps in Homogeneous Organometallic Catalysis. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2018. [DOI: 10.1016/bs.adomc.2018.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
48
|
Borgohain H, Devi R, Dheer D, Borah BJ, Shankar R, Das SK. Synthesis of Tetrahydroquinoline-Embedded Bridged Benzothiaoxazepine-1,1-dioxides. European J Org Chem 2017. [DOI: 10.1002/ejoc.201701152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Hemi Borgohain
- Department of Chemical Sciences; Tezpur University; Napaam, Tezpur Assam India-784028
| | - Runjun Devi
- Department of Chemical Sciences; Tezpur University; Napaam, Tezpur Assam India-784028
| | - Divya Dheer
- Bio-Organic Chemistry Division; Indian Institute of Integrative Medicine (CSIR); Jammu India-180001
| | - Biraj Jyoti Borah
- Department of Chemical Sciences; Tezpur University; Napaam, Tezpur Assam India-784028
| | - Ravi Shankar
- Bio-Organic Chemistry Division; Indian Institute of Integrative Medicine (CSIR); Jammu India-180001
- Academy of Scientific and Innovative Research (AcSIR); Jammu Campus India
| | - Sajal Kumar Das
- Department of Chemical Sciences; Tezpur University; Napaam, Tezpur Assam India-784028
| |
Collapse
|
49
|
Jaraíz M, Enríquez L, Pinacho R, Rubio JE, Lesarri A, López-Pérez JL. A DFT-Based Computational-Experimental Methodology for Synthetic Chemistry: Example of Application to the Catalytic Opening of Epoxides by Titanocene. J Org Chem 2017; 82:3760-3766. [PMID: 28288276 DOI: 10.1021/acs.joc.7b00220] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel DFT-based Reaction Kinetics (DFT-RK) simulation approach, employed in combination with real-time data from reaction monitoring instrumentation (like UV-vis, FTIR, Raman, and 2D NMR benchtop spectrometers), is shown to provide a detailed methodology for the analysis and design of complex synthetic chemistry schemes. As an example, it is applied to the opening of epoxides by titanocene in THF, a catalytic system with abundant experimental data available. Through a DFT-RK analysis of real-time IR data, we have developed a comprehensive mechanistic model that opens new perspectives to understand previous experiments. Although derived specifically from the opening of epoxides, the prediction capabilities of the model, built on elementary reactions, together with its practical side (reaction kinetics simulations of real experimental conditions) make it a useful simulation tool for the design of new experiments, as well as for the conception and development of improved versions of the reagents. From the perspective of the methodology employed, because both the computational (DFT-RK) and the experimental (spectroscopic data) components can follow the time evolution of several species simultaneously, it is expected to provide a helpful tool for the study of complex systems in synthetic chemistry.
Collapse
Affiliation(s)
- Martín Jaraíz
- Department of Electronics, ETSIT, University of Valladolid , Paseo Belén 15, Valladolid 47011, Spain
| | - Lourdes Enríquez
- Department of Electronics, ETSIT, University of Valladolid , Paseo Belén 15, Valladolid 47011, Spain
| | - Ruth Pinacho
- Department of Electronics, ETSIT, University of Valladolid , Paseo Belén 15, Valladolid 47011, Spain
| | - José E Rubio
- Department of Electronics, ETSIT, University of Valladolid , Paseo Belén 15, Valladolid 47011, Spain
| | - Alberto Lesarri
- Department of Physical Chemistry and Inorganic Chemistry, Faculty of Sciences, University of Valladolid , Paseo Belén 7, Valladolid 47011, Spain
| | - José L López-Pérez
- Department of Pharmaceutical Sciences - IBSAL-CIETUS, University of Salamanca , Avda. Campo Charro s/n, Salamanca 37071, Spain.,Department of Pharmacology, Faculty of Medicine, University of Panama , Panama City, Panama
| |
Collapse
|
50
|
Andreas Gansäuer. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/anie.201607115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|