Asymmetric Ring Opening/Cyclization/Retro‐Mannich Reaction of Cyclopropyl Ketones with Aryl 1, 2‐Diamines for the Synthesis of Benzimidazole Derivatives. Issue 40 (4th July 2016)

• Record Type: Journal Article
• Authors: Xia, Yong; Lin, Lili; Chang, Fenzhen; Liao, Yuting; Liu, Xiaohua; Feng, Xiaoming
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 40(2016)
• Page Start: 12228
• Page End: 12232
• Publication Date: 2016-07-04
• Subjects: asymmetric catalysis -- enantioselectivity -- heterocycles -- scandium -- small ring systems; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201604735
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A highly efficient asymmetric ring‐opening/cyclization/retro‐Mannich reaction of cyclopropyl ketones with aryl 1, 2‐diamines has been realized using a chiral N, N′ ‐dioxide/Sc III catalyst. Benzimidazoles containing chiral side chains were generated under mild reaction conditions in excellent outcomes (up to 99 % yield and 97 % ee ). This method also provides efficient access to chiral benzimidazole‐substituted amide and cycloheptene derivatives. Abstract : Scandalous Sc : The title reaction proceeds in the presence of a chiral N, N′ ‐dioxide/Sc III catalyst. A variety of benzimidazoles bearing chiral side chains were obtained with excellent results. This method provides novel access to chiral benzimidazole‐substituted amide and cycloheptene derivatives.