Enantioselective [2 + 2] Cycloaddition of Unactivated Alkenes with α-Acyloxyacroleins Catalyzed by Chiral Organoammonium Salts
作者:Kazuaki Ishihara、Kazuhiko Nakano
DOI:10.1021/ja073435w
日期:2007.7.1
enantioselective [2 + 2] cycloaddition reaction of unactivatedalkenes with α-acyloxyacroleins to give optically active 1-acyloxycyclobutanecarbaldehydes and subsequent ring expansion to give optically active 2-hydroxycyclopentanone derivatives. Organoammonium salt, H-L-Phe-L-Leu-N(CH2CH2)2-reduced triamine•2.6HNTf2, is a highly effective chiral catalyst for the above enantioselective [2 + 2] cycloaddition. Thus
Asymmetric Diels-Alder Reaction of α-Substituted and β,β-Disubstituted α,β-Enals via Diarylprolinol Silyl Ether for the Construction of All-Carbon Quaternary Stereocenters
作者:Yujiro Hayashi、Bojan P. Bondzic、Tatsuya Yamazaki、Yogesh Gupta、Shin Ogasawara、Tohru Taniguchi、Kenji Monde
DOI:10.1002/chem.201602345
日期:2016.10.24
Diels–Alder reaction of α‐substituted acrolein proceeds in the presence of the trifluoroacetic acid salt of trifluoromethyl‐substituted diarylprolinol silylether to afford the exo‐isomer with both excellent diastereoselectivity and high enantioselectivity. In the Diels–Alder reaction of a β,β‐disubstituted α,β‐unsaturated aldehyde, good exo‐selectivity and excellent enantioselectivity was obtained when the
acid–base assembly of multidentate chiral primary amines and solid polyacids is presented. A suitable structurally distinctive C2-symmetric chiral primary amine (CPA) was identified in this study and the optimal CPA–POM hybrid obtained catalyzed the Diels–Alder cycloaddition of α-substituted acroleins in high yields and fair-to-high selectivity underaqueousconditions. The primary amine in the metal–organic-framework
An enantioselective Diels–Alder reaction of 1,2-dihydropyridines with α-acyloxyacroleins catalyzed by a chiral primary ammonium salt has been developed.