1
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Iqbal SA, Uzelac M, Nawaz I, Wang Z, Jones TH, Yuan K, Millet CRP, Nichol GS, Chotana GA, Ingleson MJ. Amides as modifiable directing groups in electrophilic borylation. Chem Sci 2023; 14:3865-3872. [PMID: 37035693 PMCID: PMC10074396 DOI: 10.1039/d2sc06483a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/14/2023] [Indexed: 03/17/2023] Open
Abstract
Amide directed C-H borylation using ≥two equiv. of BBr3 forms borenium cations containing a R2N(R')C[double bond, length as m-dash]O→B(Ar)Br unit which has significant Lewis acidity at the carbonyl carbon. This enables reduction of the amide unit to an amine using hydrosilanes. This approach can be applied sequentially in a one-pot electrophilic borylation-reduction process, which for phenyl-acetylamides generates ortho borylated compounds that can be directly oxidised to the 2-(2-aminoethyl)-phenol. Other substrates amenable to the C-H borylation-reduction sequence include mono and diamino-arenes and carbazoles. This represents a simple method to make borylated molecules that would be convoluted to access otherwise (e.g. N-octyl-1-BPin-carbazole). Substituent variation is tolerated at boron as well as in the amide unit, with diarylborenium cations also amenable to reduction. This enables a double C-H borylation-reduction-hydrolysis sequence to access B,N-polycyclic aromatic hydrocarbons (PAHs), including an example where both the boron and nitrogen centres contain functionalisable handles (N-H and B-OH). This method is therefore a useful addition to the metal-free borylation toolbox for accessing useful intermediates (ArylBPin) and novel B,N-PAHs.
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Affiliation(s)
- Saqib A Iqbal
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Marina Uzelac
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Ismat Nawaz
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
- Department of Chemistry and Chemical Engineering, Lahore University of Management Sciences Lahore 54792 Pakistan
| | - Zhongxing Wang
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - T Harri Jones
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Kang Yuan
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Clement R P Millet
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Gary S Nichol
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Ghayoor Abbas Chotana
- Department of Chemistry and Chemical Engineering, Lahore University of Management Sciences Lahore 54792 Pakistan
| | - Michael J Ingleson
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
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2
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Del Giudice D, Valentini M, Sappino C, Spatola E, Murru A, Ercolani G, Di Stefano S. Controlling the Conformation of 2-Dimethylaminobiphenyls by Transient Intramolecular Hydrogen Bonding. J Org Chem 2023; 88:4379-4386. [PMID: 36926894 DOI: 10.1021/acs.joc.2c02992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
Temporal control of molecular motions is receiving increasing attention because it is central to the development of molecular switches and motors and nanoscopic materials with life-like properties. Inspired by previous studies, here, we report that acid 12 can be used to temporally control the conformational freedom around the C-C bond connecting the two aromatic rings of the ditopic bases 4 and 5. Consistent with NMR measurements and DFT calculations, before fuel addition, the conformational motion of the two aromatic rings of both 4 and 5 mainly consists of a large amplitude torsional oscillation spanning about 260° and passing for the anti conformation (the two nitrogen atoms at opposite sides). Immediately after the addition of 12, due to the protonation of one nitrogen and consequent formation of an N-H···N intramolecular hydrogen bond, the torsional oscillation in both 4H+ and 5H+ is not only restricted to a smaller range (about 100°) but explores the previously forbidden conformational space around the syn conformation (the two nitrogen atoms at the same side). However, the new state is an out-of-equilibrium state since decarboxylation of the conjugate base of 12 takes place and, at the end of the process, the system reverts to the more conformationally mobile state.
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Affiliation(s)
- Daniele Del Giudice
- Dipartimento di Chimica, Università di Roma La Sapienza and ISB-CNR Sede Secondaria di Roma - Meccanismi di Reazione, P.le A. Moro 5, I-00185 Roma, Italy
| | - Matteo Valentini
- Dipartimento di Chimica, Università di Roma La Sapienza and ISB-CNR Sede Secondaria di Roma - Meccanismi di Reazione, P.le A. Moro 5, I-00185 Roma, Italy
| | - Carla Sappino
- Dipartimento di Chimica, Università di Roma La Sapienza and ISB-CNR Sede Secondaria di Roma - Meccanismi di Reazione, P.le A. Moro 5, I-00185 Roma, Italy
| | - Emanuele Spatola
- Dipartimento di Chimica, Università di Roma La Sapienza and ISB-CNR Sede Secondaria di Roma - Meccanismi di Reazione, P.le A. Moro 5, I-00185 Roma, Italy
| | - Aurora Murru
- Dipartimento di Chimica, Università di Roma La Sapienza and ISB-CNR Sede Secondaria di Roma - Meccanismi di Reazione, P.le A. Moro 5, I-00185 Roma, Italy
| | - Gianfranco Ercolani
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Roma, Italy
| | - Stefano Di Stefano
- Dipartimento di Chimica, Università di Roma La Sapienza and ISB-CNR Sede Secondaria di Roma - Meccanismi di Reazione, P.le A. Moro 5, I-00185 Roma, Italy
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3
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Rej S, Chatani N. Regioselective Transition‐Metal‐Free C(sp
2
)−H Borylation: A Subject of Practical and Ongoing Interest in Synthetic Organic Chemistry. Angew Chem Int Ed Engl 2022; 61:e202209539. [DOI: 10.1002/anie.202209539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Indexed: 12/22/2022]
Affiliation(s)
- Supriya Rej
- Department of Applied Chemistry Faculty of Engineering and Research Center for Environmental Preservation Osaka University Suita, Osaka 565-0871 Japan
- Institut für Chemie Technische Universität Berlin Strasse des 17. Juni 115 10623 Berlin Germany
| | - Naoto Chatani
- Department of Applied Chemistry Faculty of Engineering and Research Center for Environmental Preservation Osaka University Suita, Osaka 565-0871 Japan
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4
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Rej S, Chatani N. Regio‐Selective Transition‐Metal‐Free C(sp2)‒H Borylation: A Subject of Practical and Ongoing Interest in Synthetic Organic Chemistry. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202209539] [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]
Affiliation(s)
- Supriya Rej
- Osaka University School of Engineering Graduate School of Engineering: Osaka Daigaku Kogakubu Daigakuin Kogaku Kenkyuka Applied Chemistry JAPAN
| | - Naoto Chatani
- Osaka University School of Engineering Graduate School of Engineering: Osaka Daigaku Kogakubu Daigakuin Kogaku Kenkyuka Applied Chemistry 2-1 Yamadaoka 566-0871 Suita, Osaka JAPAN
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5
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Sans-Panadés E, Vaquero JJ, Fernández-Rodríguez MA, García-García P. Synthesis of BN-Polyarenes by a Mild Borylative Cyclization Cascade. Org Lett 2022; 24:5860-5865. [PMID: 35913827 PMCID: PMC9384698 DOI: 10.1021/acs.orglett.2c02477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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Reaction of BCl3 with suitably substituted o-alkynylanilines promotes a cascade reaction in which BN-polycyclic
compounds are obtained via the formation of two new cycles and three
new bonds in a single operational step. The reaction is highly efficient
and takes place at room temperature, providing a very mild and straightforward
strategy for the preparation of BN-aromatic compounds, which can be
further transformed into a variety of BN-PAHs with different polycyclic
cores and substituents.
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Affiliation(s)
- Ester Sans-Panadés
- Universidad de Alcalá (IRYCIS). Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR). Campus Científico-Tecnológico, Facultad de Farmacia. Autovía A-II, Km 33.1, 28805-Alcalá de Henares, Madrid, Spain
| | - Juan J Vaquero
- Universidad de Alcalá (IRYCIS). Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR). Campus Científico-Tecnológico, Facultad de Farmacia. Autovía A-II, Km 33.1, 28805-Alcalá de Henares, Madrid, Spain
| | - Manuel A Fernández-Rodríguez
- Universidad de Alcalá (IRYCIS). Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR). Campus Científico-Tecnológico, Facultad de Farmacia. Autovía A-II, Km 33.1, 28805-Alcalá de Henares, Madrid, Spain
| | - Patricia García-García
- Universidad de Alcalá (IRYCIS). Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR). Campus Científico-Tecnológico, Facultad de Farmacia. Autovía A-II, Km 33.1, 28805-Alcalá de Henares, Madrid, Spain
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6
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Jin JL, Yang L, Ding X, Ou LH, Chen YD, Gu HY, Wu Y, Geng Y. Density Functional Studies on Photophysical Properties of Boron-Pyridyl-Imino-Isoindoline Dyes: Effect of the Fusion. ACS OMEGA 2020; 5:21067-21075. [PMID: 32875243 PMCID: PMC7450629 DOI: 10.1021/acsomega.0c02669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
In this work, to make out the aryl-fusion effect on the photophysical properties of boron-pyridyl-imino-isoindoline dyes, compounds 1-5 were theoretically studied through analyses of their geometric and electronic structures, optical properties, transport abilities, and radiative (k r) and non-radiative decay rate (k nr) constants. The highest occupied molecular orbitals of aryl-fused compounds 2-5 are higher owing to the extended conjugation. Interestingly, aryl fusion in pyridyl increases the lowest unoccupied molecular orbital (LUMO) level, while isoindoline decreases the LUMO level; thus, 4 and 5 with aryl fusion both in pyridyl and isoindoline exhibit a similar LUMO to 1. Compounds 4 and 5 show relatively low ionization potentials and high electron affinities, suggesting a better ability to inject holes and electrons. Importantly, the aryl fusion is conducive to the decrease of k IC. The designed compound 5 exhibits a red-shifted emission maximum, low λh, and low k IC, which endow it with great potential for applications in organic electronics. Our investigation provides an in-depth understanding of the aryl-fusion effect on boron-pyridyl-imino-isoindoline dyes at molecular levels and demonstrates that it is achievable.
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Affiliation(s)
- Jun-Ling Jin
- Hunan
Provincial Key Laboratory of Water Treatment Functional Materials,
Hunan Province Engineering Research Center of Electroplating Wastewater
Reuse Technology, Province Cooperative Innovation Center for the Construction
& Development of Dongting Lake Ecological Economic Zone, College
of Chemistry and Materials Engineering, Hunan University of Arts and Science, Changde, 415000, Hunan, China
| | - Lixia Yang
- Hunan
Provincial Key Laboratory of Water Treatment Functional Materials,
Hunan Province Engineering Research Center of Electroplating Wastewater
Reuse Technology, Province Cooperative Innovation Center for the Construction
& Development of Dongting Lake Ecological Economic Zone, College
of Chemistry and Materials Engineering, Hunan University of Arts and Science, Changde, 415000, Hunan, China
| | - Xiang Ding
- Hunan
Provincial Key Laboratory of Water Treatment Functional Materials,
Hunan Province Engineering Research Center of Electroplating Wastewater
Reuse Technology, Province Cooperative Innovation Center for the Construction
& Development of Dongting Lake Ecological Economic Zone, College
of Chemistry and Materials Engineering, Hunan University of Arts and Science, Changde, 415000, Hunan, China
| | - Li-Hui Ou
- Hunan
Provincial Key Laboratory of Water Treatment Functional Materials,
Hunan Province Engineering Research Center of Electroplating Wastewater
Reuse Technology, Province Cooperative Innovation Center for the Construction
& Development of Dongting Lake Ecological Economic Zone, College
of Chemistry and Materials Engineering, Hunan University of Arts and Science, Changde, 415000, Hunan, China
| | - Yuan-Dao Chen
- Hunan
Provincial Key Laboratory of Water Treatment Functional Materials,
Hunan Province Engineering Research Center of Electroplating Wastewater
Reuse Technology, Province Cooperative Innovation Center for the Construction
& Development of Dongting Lake Ecological Economic Zone, College
of Chemistry and Materials Engineering, Hunan University of Arts and Science, Changde, 415000, Hunan, China
| | - Hao-Yu Gu
- Institute
of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Yong Wu
- Institute
of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Yun Geng
- Institute
of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun, 130024, Jilin, China
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7
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Zhang J, Chang S. cine-Silylative Ring-Opening of α-Methyl Azacycles Enabled by the Silylium-Induced C-N Bond Cleavage. J Am Chem Soc 2020; 142:12585-12590. [PMID: 32627547 DOI: 10.1021/jacs.0c05241] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Described herein is the development of a borane-catalyzed cine-silylative ring-opening of α-methyl azacycles. This transformation involves four-step cascade processes: (i) exo-dehydrogenation of alicyclic amine, (ii) hydrosilylation of the resultant enamine, (iii) silylium-induced cis-β-amino elimination to open the ring skeleton, and (iv) hydrosilylation of the terminal olefin. The present borane catalysis also works efficiently for the C-N bond cleavage of acyclic tertiary amines. On the basis of experimental and computational studies, the silicon atom was elucidated to play a pivotal role in the β-amino elimination step.
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Affiliation(s)
- Jianbo Zhang
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea.,Department of Chemistry, Korea Advanced Institute of Science & Technology (KAIST), Daejeon 34141, South Korea
| | - Sukbok Chang
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea.,Department of Chemistry, Korea Advanced Institute of Science & Technology (KAIST), Daejeon 34141, South Korea
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8
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Iqbal SA, Pahl J, Yuan K, Ingleson MJ. Intramolecular (directed) electrophilic C-H borylation. Chem Soc Rev 2020; 49:4564-4591. [PMID: 32495755 DOI: 10.1039/c9cs00763f] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
The intramolecular C-H borylation of (hetero)arenes and alkenes using electrophilic boranes is a powerful transition metal free methodology for forming C-B bonds. These C-H borylation reactions are preceded by intermolecular bond (both dative and covalent) formation, with examples proceeding via initial C-B and N-B bond formation dominating this field thus both are discussed in depth herein. Less prevalent intramolecular electrophilic C-H borylation reactions that proceed by intermolecular O-B, S-B and P-B bond formation are also summarised. Mechanistic studies are presented that reveal two mechanisms for C-H borylation, (i) electrophilic aromatic substitution (prevalent with B-X electrophiles); (ii) σ-bond metathesis mediated (prevalent with B-H and B-R electrophiles). To date, intramolecular electrophilic C-H borylation is utilised mainly for accessing boron containing conjugated organic materials, however recent developments, summarized herein alongside early studies, have highlighted the applicability of this methodology for forming synthetically versatile organo-boronate esters and boron containing bioactives. The multitude of synthetic procedures reported for intramolecular electrophilic C-H borylation contain many common features and this enables key requirements for successful C-H borylation and the factors effecting regioselectivity and substrate scope to be identified, discussed and summarized.
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Affiliation(s)
- S A Iqbal
- EastCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK.
| | - J Pahl
- EastCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK.
| | - K Yuan
- EastCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK.
| | - M J Ingleson
- EastCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK.
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9
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Banerjee S, Vivek Kumar S, Punniyamurthy T. Site-Selective Rh-Catalyzed C-7 and C-6 Dual C–H Functionalization of Indolines: Synthesis of Functionalized Pyrrolocarbazoles. J Org Chem 2020; 85:2793-2805. [DOI: 10.1021/acs.joc.9b03180] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Sonbidya Banerjee
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Sundaravel Vivek Kumar
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, India
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10
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Patrick EA, Piers WE. Twenty-five years of bis-pentafluorophenyl borane: a versatile reagent for catalyst and materials synthesis. Chem Commun (Camb) 2020; 56:841-853. [DOI: 10.1039/c9cc08338c] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Highlights of the extensive chemistry and applications of bis-pentafluorophenyl borane (“Piers’ borane”) from the 25 years since its first appearance are featured.
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