1
|
Zhang QB, Li F, Pan B, Yu L, Yue XG. Visible-Light-Mediated [2+2] Photocycloadditions of Alkynes. Chemistry 2024; 30:e202401501. [PMID: 38806409 DOI: 10.1002/chem.202401501] [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: 04/17/2024] [Revised: 05/21/2024] [Accepted: 05/27/2024] [Indexed: 05/30/2024]
Abstract
Visible-light-mediated [2+2] photocycloaddition reaction can be considered an ideal solution due to its green and sustainable properties, and is one of the most efficient methods to synthesize four-membered ring motifs. Although research on the [2+2] photocycloaddition of alkynes is challenging because of the diminished reactivity of alkynes, and the more significant ring strain of the products, remarkable achievements have been made in this field. In this article, we highlight the recent advances in visible-light-mediated [2+2] photocycloaddition reactions of alkynes, with focus on the reaction mechanism and the late-stage synthetic applications. Advances in obtaining cyclobutenes, azetines, and oxetene active intermediates continue to be breakthroughs in this fascinating field of research.
Collapse
Affiliation(s)
- Qing-Bao Zhang
- Shandong Peninsula Engineering Research Center of Comprehensive Brine Utilization, Weifang University of Science and Technology, Shouguang, CN, 262700, People's Republic of China
| | - Feng Li
- Shandong Peninsula Engineering Research Center of Comprehensive Brine Utilization, Weifang University of Science and Technology, Shouguang, CN, 262700, People's Republic of China
| | - Bin Pan
- Shandong Peninsula Engineering Research Center of Comprehensive Brine Utilization, Weifang University of Science and Technology, Shouguang, CN, 262700, People's Republic of China
| | - Lei Yu
- Shandong Peninsula Engineering Research Center of Comprehensive Brine Utilization, Weifang University of Science and Technology, Shouguang, CN, 262700, People's Republic of China
| | - Xiang-Guo Yue
- Shandong Peninsula Engineering Research Center of Comprehensive Brine Utilization, Weifang University of Science and Technology, Shouguang, CN, 262700, People's Republic of China
| |
Collapse
|
2
|
Trauner F, Ghazali R, Rettig J, Thiele CM, Didier D. Stereoselective polar radical crossover for the functionalization of strained-ring systems. Commun Chem 2024; 7:139. [PMID: 38898159 PMCID: PMC11187220 DOI: 10.1038/s42004-024-01221-3] [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: 01/18/2024] [Accepted: 06/06/2024] [Indexed: 06/21/2024] Open
Abstract
Radical-polar crossover of organoborates is a poweful tool that enables the creation of two C-C bonds simultaneously. Small ring systems have become essential motifs in drug discovery and medicinal chemistry. However, step-economic methods for their selective functionalization remains scarce. Here we present a one-pot strategy that merges a simple preparation of strained organoboron species with the recently popularized polar radical crossover of borate derivatives to stereoselectively access tri-substituted azetidines, cyclobutanes and five-membered carbo- and heterocycles.
Collapse
Affiliation(s)
- Florian Trauner
- Technische Universität Darmstadt, Clemens-Schöpf-Insitut für Organische Chemie und Biochemie, Peter-Grünberg-Str. 4, 64287, Darmstadt, Germany
- Ludwig-Maximilians Universität, Department Chemie, Butenandtstr. 5, 81377, München, Germany
| | - Rahma Ghazali
- Technische Universität Darmstadt, Clemens-Schöpf-Insitut für Organische Chemie und Biochemie, Peter-Grünberg-Str. 4, 64287, Darmstadt, Germany
| | - Jan Rettig
- Technische Universität Darmstadt, Clemens-Schöpf-Insitut für Organische Chemie und Biochemie, Peter-Grünberg-Str. 4, 64287, Darmstadt, Germany
| | - Christina M Thiele
- Technische Universität Darmstadt, Clemens-Schöpf-Insitut für Organische Chemie und Biochemie, Peter-Grünberg-Str. 4, 64287, Darmstadt, Germany
| | - Dorian Didier
- Technische Universität Darmstadt, Clemens-Schöpf-Insitut für Organische Chemie und Biochemie, Peter-Grünberg-Str. 4, 64287, Darmstadt, Germany.
- Ludwig-Maximilians Universität, Department Chemie, Butenandtstr. 5, 81377, München, Germany.
| |
Collapse
|
3
|
Konowalchuk DJ, Hall DG. Divergent Synthesis of 1,2,3,4-Tetrasubstituted Cyclobutenes from a Common Scaffold: Enantioselective Desymmetrization by Dual-Catalyzed Photoredox Cross-Coupling. Angew Chem Int Ed Engl 2023; 62:e202313503. [PMID: 37852934 DOI: 10.1002/anie.202313503] [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: 09/12/2023] [Revised: 10/12/2023] [Accepted: 10/17/2023] [Indexed: 10/20/2023]
Abstract
Four-membered carbocycles are important structural motifs found in several natural products and drugs. Amongst those, cyclobutenes are attractive intermediates because the residual olefin can be manipulated selectively into various saturated and unsaturated analogs. Few methods exist to access chiral tri- and tetra-C-substituted cyclobutenes and they are generally limited in terms of diversification. Herein, a divergent synthetic strategy was developed where a single optically enriched scaffold is diversified into a variety of derivatives with different substitution patterns. To this end, the enantioselective desymmetrization of prochiral 1,2-dibromocyclobutene imides was enabled by a dual Ir/Ni-catalyzed photoredox C(sp2 )-C(sp3 ) cross-coupling with an alkyltrifluoroborate salt to install a convertible carbon fragment in good yields and >90 % enantiomeric excess. Exceptional mono-coupling selectivity is observed and the resulting chiral bromocyclobutene serves as a common scaffold that can be transformed in a divergent manner into several valuable 1,2,3,4-tetra-C-substituted cyclobutane products while maintaining optical purity.
Collapse
Affiliation(s)
- Dawson J Konowalchuk
- Department of Chemistry, 4-010 Centennial Centre for Interdisciplinary Science, University of Alberta, 11335 Saskatchewan Dr NW, T6G 2G2, Edmonton, AB, Canada
| | - Dennis G Hall
- Department of Chemistry, 4-010 Centennial Centre for Interdisciplinary Science, University of Alberta, 11335 Saskatchewan Dr NW, T6G 2G2, Edmonton, AB, Canada
| |
Collapse
|
4
|
Chen J, Zhou Q, Fang H, Lu P. Dancing on Ropes ‐ Enantioselective Functionalization of Preformed Four‐membered Carbocycles. CHINESE J CHEM 2022. [DOI: 10.1002/cjoc.202100879] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jun Chen
- Research Center for Molecular Recognition and Synthesis, Department of Chemistry, Fudan University, 220 Handan Lu Shanghai 200433 China
| | - Qiang Zhou
- Research Center for Molecular Recognition and Synthesis, Department of Chemistry, Fudan University, 220 Handan Lu Shanghai 200433 China
| | - Huayi Fang
- School of Materials Science and Engineering, Tianjin Key Lab for Rare Earth Materials and Applications, Nankai University, No 38 Tongyan Road Tianjin 300350 China
| | - Ping Lu
- Research Center for Molecular Recognition and Synthesis, Department of Chemistry, Fudan University, 220 Handan Lu Shanghai 200433 China
| |
Collapse
|
5
|
Ozawa Y, Endo K, Ito H. Regio- and Stereoselective Synthesis of Multi-Alkylated Allylic Boronates through Three-Component Coupling Reactions between Allenes, Alkyl Halides, and a Diboron Reagent. J Am Chem Soc 2021; 143:13865-13877. [PMID: 34424698 DOI: 10.1021/jacs.1c06538] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Multisubstituted allylic boronates are attractive and valuable precursors for the rapid and stereoselective construction of densely substituted carbon skeletons. Herein, we report the first synthetic approach for differentially 2,3,3-trialkyl-substituted allylic boronates that contain a stereodefined tetrasubstituted alkene structure. Copper(I)-catalyzed regio- and stereoselective three-component coupling reactions between gem-dialkylallenes, alkyl halides, and a diboron reagent afforded sterically congested allylic boronates. The allylboration of aldehydes diastereoselectively furnished the corresponding homoallylic alcohols that bear a quaternary carbon. A computational study revealed that the selectivity-determining mechanism was correlated to the coordination of a boryl copper(I) species to the allene substrate as well as the borylcupration step.
Collapse
Affiliation(s)
- Yu Ozawa
- Division of Applied Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Kohei Endo
- Division of Applied Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Hajime Ito
- Division of Applied Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.,Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| |
Collapse
|
6
|
Didier D, Reiners F. Uncommon Four-Membered Building Blocks - Cyclobutenes, Azetines and Thietes. CHEM REC 2021; 21:1144-1160. [PMID: 33734571 DOI: 10.1002/tcr.202100011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 12/15/2022]
Abstract
Strained ring systems have gained considerable importance over the last few years for their implication in natural product syntheses or in drug discovery programs. We present herein a recollection of our work on the construction and functionalization of unsaturated four-membered carbo- and heterocycles in the context of the literature, as well as their applications in further reactions.
Collapse
Affiliation(s)
- Dorian Didier
- Department of Chemistry, Ludwig-Maximilians Universität, Butenandtstraße 5-13, 81377, Munich, Germany
| | - Felix Reiners
- Department of Chemistry, Ludwig-Maximilians Universität, Butenandtstraße 5-13, 81377, Munich, Germany
| |
Collapse
|
7
|
Reiners F, Joseph E, Nißl B, Didier D. Stereoselective Access to Azetidine-Based α-Amino Acids and Applications to Small Peptide Synthesis. Org Lett 2020; 22:8533-8537. [PMID: 33052683 DOI: 10.1021/acs.orglett.0c03131] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Non-natural azetidine-based amino acids (Aze) present interesting features in protein engineering. A simple organometallic route toward unsaturated carboxylic acid precursors is presented. Subsequent metal-catalyzed asymmetric reduction allowed for the synthesis of a new library of 2-azetidinylcarboxylic acids, which were finally employed in the formation of small peptide chains.
Collapse
Affiliation(s)
- Felix Reiners
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Emanuel Joseph
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Benedikt Nißl
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Dorian Didier
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 Munich, Germany
| |
Collapse
|
8
|
Music A, Baumann AN, Spieß P, Hilgert N, Köllen M, Didier D. Single-Pot Access to Bisorganoborinates: Applications in Zweifel Olefination. Org Lett 2019; 21:2189-2193. [PMID: 30864807 DOI: 10.1021/acs.orglett.9b00493] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Zweifel olefination is a catalyst-free reaction that serves alkene functionalization. While most methods employ commercially available boron pinacol esters, we have assembled a sequence in which the two partners of the formal coupling reaction are installed successively, starting from inexpensive boron alkoxides. The in situ formation of bisorganoborinates was accomplished by consecutive reaction of two different organometallic species. This single-pot procedure represents a great advancement in the generation of organoborinates and their involvement in C-C bond formation.
Collapse
Affiliation(s)
- Arif Music
- Department of Chemistry and Pharmacy , Ludwig-Maximilians-Universität München , Butenandtstraße 5-13 , 81377 Munich , Germany
| | - Andreas N Baumann
- Department of Chemistry and Pharmacy , Ludwig-Maximilians-Universität München , Butenandtstraße 5-13 , 81377 Munich , Germany
| | - Philipp Spieß
- Department of Chemistry and Pharmacy , Ludwig-Maximilians-Universität München , Butenandtstraße 5-13 , 81377 Munich , Germany
| | - Nicolas Hilgert
- Department of Chemistry and Pharmacy , Ludwig-Maximilians-Universität München , Butenandtstraße 5-13 , 81377 Munich , Germany
| | - Martin Köllen
- Department of Chemistry and Pharmacy , Ludwig-Maximilians-Universität München , Butenandtstraße 5-13 , 81377 Munich , Germany
| | - Dorian Didier
- Department of Chemistry and Pharmacy , Ludwig-Maximilians-Universität München , Butenandtstraße 5-13 , 81377 Munich , Germany
| |
Collapse
|
9
|
Eisold M, Müller-Deku A, Reiners F, Didier D. Parallel Approaches for the Functionalization of Thietes: α-Metalation versus C–H Activation. Org Lett 2018; 20:4654-4658. [DOI: 10.1021/acs.orglett.8b01961] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Michael Eisold
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Adrian Müller-Deku
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Felix Reiners
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Dorian Didier
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| |
Collapse
|
10
|
Baumann AN, Schüppel F, Eisold M, Kreppel A, de Vivie-Riedle R, Didier D. Oxidative Ring Contraction of Cyclobutenes: General Approach to Cyclopropylketones including Mechanistic Insights. J Org Chem 2018; 83:4905-4921. [DOI: 10.1021/acs.joc.8b00297] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andreas N. Baumann
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Franziska Schüppel
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Michael Eisold
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Andrea Kreppel
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Regina de Vivie-Riedle
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Dorian Didier
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstraße 5-13, 81377 Munich, Germany
| |
Collapse
|
11
|
Lewis Acid-Catalyzed Yne-Carbonyl Metathesis of Ynamides and Cyclobutanones: Facile Synthesis of Functionalized Alkylidenecyclobutanes. ASIAN J ORG CHEM 2018. [DOI: 10.1002/ajoc.201700709] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
12
|
Eisold M, Didier D. Stereoselective Access to Alkylidenecyclobutanes through γ-Selective Cross-Coupling Strategies. Org Lett 2017; 19:4046-4049. [PMID: 28726420 DOI: 10.1021/acs.orglett.7b01803] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alkylidenecyclobutanes (ACBs) containing all-carbon quaternary stereocenters were simply and efficiently synthesized by combining boron-homologation and γ-selective cross-coupling strategies. This unique sequence led to excellent regio- and diastereoselectivities in the generation of targeted four-membered rings with up to 99% enantiomeric excess using chiral substrates. In addition to the original synthesis of ACBs, the first asymmetric catalytic formation of quaternary stereocenters based on γ-selective cross-coupling reactions is finally shown.
Collapse
Affiliation(s)
- Michael Eisold
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University , Butenandtstraße 5-13, 81377 Munich, Germany
| | - Dorian Didier
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University , Butenandtstraße 5-13, 81377 Munich, Germany
| |
Collapse
|
13
|
Alcaide B, Almendros P, Lázaro-Milla C. Regioselective Synthesis of Heteroatom-Functionalized Cyclobutene-triflones and Cyclobutenones. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201700492] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Benito Alcaide
- Grupo de Lactamas y Heterociclos Bioactivos; Departamento de Química Orgánica I; Unidad Asociada al CSIC; Facultad de Química; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Pedro Almendros
- Instituto de Química Orgánica General; Consejo Superior de Investigaciones Científicas; IQOG-CSIC; Juan de la Cierva 3 28006 Madrid Spain
| | - Carlos Lázaro-Milla
- Grupo de Lactamas y Heterociclos Bioactivos; Departamento de Química Orgánica I; Unidad Asociada al CSIC; Facultad de Química; Universidad Complutense de Madrid; 28040 Madrid Spain
| |
Collapse
|
14
|
Baumann AN, Eisold M, Didier D. Stereoselective Sequence toward Biologically Active Fused Alkylidenecyclobutanes. Org Lett 2017; 19:2114-2117. [PMID: 28374585 DOI: 10.1021/acs.orglett.7b00724] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Combining an efficient preparation of cyclobutenylmetal species, high-yielding cross-coupling reactions, and highly diastereoselective [4 + 2]-cycloaddition led to opening a new route toward the synthesis of fused alkylidenecyclobutanes containing up to five consecutive stereocenters. New complex architectures, analogues to protoilludane skeletons, were obtained in a very efficient manner and with a minimum number of steps starting from commercial sources and were tested for their cytotoxicity against leukemia cell lines HL60.
Collapse
Affiliation(s)
- Andreas N Baumann
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University , Butenandtstraße 5-13, 81377 Munich, Germany
| | - Michael Eisold
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University , Butenandtstraße 5-13, 81377 Munich, Germany
| | - Dorian Didier
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University , Butenandtstraße 5-13, 81377 Munich, Germany
| |
Collapse
|
15
|
Mei H, Lin L, Wang L, Dai L, Liu X, Feng X. Highly regio-, diastereo- and enantioselective deracemization of axially chiral 3-alkylideneoxindoles. Chem Commun (Camb) 2017; 53:8763-8766. [DOI: 10.1039/c7cc05164f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A variety of (Z)-4-alkyl-2-((3-oxo-1,3-diarylpropyl)cyclohexylidene)-indolin-2-ones with three stereogenic centers at ξ-, γ- and δ′-positions were obtained in up to 95% yield, 98% ee and 99/1 dr in the presence of L-PiPh/Sc(iii).
Collapse
Affiliation(s)
- Hongjiang Mei
- Key Laboratory of Green Chemistry & Technology
- Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
| | - Lili Lin
- Key Laboratory of Green Chemistry & Technology
- Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
| | - Lifeng Wang
- Key Laboratory of Green Chemistry & Technology
- Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
| | - Li Dai
- Key Laboratory of Green Chemistry & Technology
- Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
| | - Xiaohua Liu
- Key Laboratory of Green Chemistry & Technology
- Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
| | - Xiaoming Feng
- Key Laboratory of Green Chemistry & Technology
- Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
| |
Collapse
|
16
|
Eisold M, Baumann AN, Kiefl GM, Emmerling ST, Didier D. Unsaturated Four-Membered Rings: Efficient Strategies for the Construction of Cyclobutenes and Alkylidenecyclobutanes. Chemistry 2016; 23:1634-1644. [PMID: 27862444 DOI: 10.1002/chem.201604585] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Indexed: 01/08/2023]
Abstract
Our recent studies of the diastereo- and enantioselective formation of strained alkylidenecycloalkanes drove us to more-thoroughly investigate the formation of four-membered rings for which only few efficient methods are described. We first developed a strategy to diversify the saturated part of the four-membered ring and applied it to a highly diastereoselective synthesis of more-elaborate alkylidenecyclobutanes, which completed our precedent studies. In parallel, cyclobutene structures were built employing simple organometallic methods and further functionalized to give a diverse range of new substitution patterns, which consequently enriched the pool of cyclobutene-based building blocks.
Collapse
Affiliation(s)
- Michael Eisold
- Department of Chemistry and Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Andreas N Baumann
- Department of Chemistry and Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Gabriel M Kiefl
- Department of Chemistry and Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Sebastian T Emmerling
- Department of Chemistry and Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Dorian Didier
- Department of Chemistry and Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| |
Collapse
|