Perfluorinated Aryls in the Design of Chiral Brønsted Acid Catalysts: Catalysis of Enantioselective [4 + 2] Cycloadditions and Ene Reactions of Imines with Alkenes by Chiral Mono-Phosphoric Acids with
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- 作者：Norie Momiyama ; Hiroshi Okamoto ; Jun Kikuchi ; Toshinobu Korenaga ; Masahiro Terada
- 刊名：ACS Catalysis
- 出版年：2016
- 出版时间：February 5, 2016
- 年：2016
- 卷：6
- 期：2
- 页码：1198-1204
- 全文大小：488K
- ISSN：2155-5435
文摘
Perfluorinated aryl-incorporating chiral monophosphoric acids were used for highly stereoselective reactions of N-acyl and N-acyloxy aldimines with styrenes. Their electronic and steric profiles were established in comparison with those of phenyl, binaphthyl, and partially fluorinated aryls. The [4 + 2] cycloaddition reactions of N-benzoyl aldimines with alkenes proceeded with excellent diastereo- and enantioselectivities in the presence of the perfluorophenyl-incorporating chiral monophosphoric acid catalysts 1a and 1c. The stereoselective elaboration of polysubstituted cycloadducts to amines is described. The imino–ene reactions of N-Fmoc imines with alkenes have been successfully developed in a three-component manner. This process uses aldehydes, 9-fluorenylmethyl carbamate, and alkenes in the presence of a chiral monophosphoric acid catalyst, 2a, possessing an F10binaphthyl skeleton.