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Vinayagam V, Karre SK, Kasu SR, Srinath R, Naveen Babu Bathula HS, Sadhukhan SK. AlCl 3-Mediated CHF 2 Transfer and Cyclocondensation of Difluoromethoxy Functionalized o-Phenylenediamines to Access N-Substituted Benzimidazoles. Org Lett 2022; 24:6142-6147. [PMID: 35938941 DOI: 10.1021/acs.orglett.2c02231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Herein, we report for the first time a transition-metal-free frustrated Lewis pair (FLP) catalyzed CHF2 group migration from an oxygen atom to the neighboring nitrogen atom, which led to the synthesis of N-substituted benzimidazoles at room temperature with excellent yields, broad functional group tolerance, and a short reaction time. The oxygen-attached difluoromethane acted as a C1 source in the synthesis of N-substituted benzimidazoles in the presence of AlCl3 by cleaving one C-O bond and two C-F bonds, resulting in formation of two new C-N bonds.
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Affiliation(s)
- Vinothkumar Vinayagam
- Curia India Pvt. Ltd (Formerly Albany Molecular Research, Hyderabad Research Centre), MN Park, Genome Valley, Shameerpet, RR District, Hyderabad 500078, India
| | - Satish Kumar Karre
- Curia India Pvt. Ltd (Formerly Albany Molecular Research, Hyderabad Research Centre), MN Park, Genome Valley, Shameerpet, RR District, Hyderabad 500078, India
| | - Sreenivasa Reddy Kasu
- Curia India Pvt. Ltd (Formerly Albany Molecular Research, Hyderabad Research Centre), MN Park, Genome Valley, Shameerpet, RR District, Hyderabad 500078, India
| | - Ravuri Srinath
- Curia India Pvt. Ltd (Formerly Albany Molecular Research, Hyderabad Research Centre), MN Park, Genome Valley, Shameerpet, RR District, Hyderabad 500078, India
| | - Hema Sundar Naveen Babu Bathula
- Curia India Pvt. Ltd (Formerly Albany Molecular Research, Hyderabad Research Centre), MN Park, Genome Valley, Shameerpet, RR District, Hyderabad 500078, India
| | - Subir Kumar Sadhukhan
- Curia India Pvt. Ltd (Formerly Albany Molecular Research, Hyderabad Research Centre), MN Park, Genome Valley, Shameerpet, RR District, Hyderabad 500078, India
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Isfeld KA, Killeen C, Konowalchuk DJ, Davis RL. Exploring the catalytic role of the guanidine TBD in carboxylative cyclizations. Org Biomol Chem 2022; 20:5730-5734. [PMID: 35852820 DOI: 10.1039/d2ob01012g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Employing a combination of mechanistic, kinetic and computational studies we have examined the mechanism of the TBD-catalyzed carboxylative cyclization of indole derivatives. Our studies provide insight into the role of the guanidine superbase TBD in catalyzing C-C bond formation between indole derivatives and CO2.
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Affiliation(s)
- Kaitlin A Isfeld
- Chemistry Department, University of Manitoba, 360 Parker Building, 144 Dysart Road, Winnipeg, Manitoba, Canada R3T 2N2.
| | - Charles Killeen
- Chemistry Department, University of Manitoba, 360 Parker Building, 144 Dysart Road, Winnipeg, Manitoba, Canada R3T 2N2.
| | - Dawson J Konowalchuk
- Chemistry Department, University of Manitoba, 360 Parker Building, 144 Dysart Road, Winnipeg, Manitoba, Canada R3T 2N2.
| | - Rebecca L Davis
- Chemistry Department, University of Manitoba, 360 Parker Building, 144 Dysart Road, Winnipeg, Manitoba, Canada R3T 2N2.
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Abstract
Formic acid (HCOOH) as an inexpensive and versatile reagent has gained broad
attention in the field of green synthesis and chemical industry. Formic acid acts not only as a
convenient and less toxic CO surrogate, but also as an excellent formylative reagent, C1
source and hydrogen donor in organic reactions. Over the past decades, many exciting contributions
have been made which have helped chemists to understand the mechanisms of these
reactions. The review will examine recent advances in the utilization of formic acid as an
economical, practical and multipurpose reactant in synthetic transformations.
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Affiliation(s)
- Xiao-Hua Cai
- School of Chemical Engineering, Guizhou Minzu University, Guiyang 550025, China
| | - Su-qian Cai
- School of Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 117004, China
| | - Bing Xie
- School of Chemical Engineering, Guizhou Minzu University, Guiyang 550025, China
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