N-Heterocyclic Carbene-Catalyzed Double Michael Addition: Stereoselective Synthesis of Spirofluorenes and Multisubstituted Indanes
作者:Fen Xing、Ze-Nan Feng、Ying Wang、Guang-Fen Du、Cheng-Zhi Gu、Bin Dai、Lin He
DOI:10.1002/adsc.201701269
日期:2018.4.17
The strong Brønsted basic character of N‐heterocyclic carbenes (NHCs) has been used to promote the cascade doubleMichaeladdition between fluorenes and dienones. Under catalyst loadings of 1–5 mol% of NHC, fluorene reacts with divinyl ketones (DVKs) to afford anti‐spirofluorene compounds in high yields. However, when benzenedi(enones) were employed as Michael acceptors in the presence of 10 mol% of
作者:Ze-Nan Feng、Jin-Yun Luo、Yang Zhang、Guang-Fen Du、Lin He
DOI:10.1039/c9ob00210c
日期:——
N-Heterocyclic carbene (NHC)-catalyzed diastereoselectivesynthesis of multisubstituted sulfenylated indanes has been developed. In the presence of 1 mol% NHC, various thiols underwent the sulfa-Michael–Michael cascade reaction with benzenedi(enones) efficiently to form the carbon–sulfur bond and construct sulfenylated indanes in good to excellent yields with high diastereoselectivity. In addition, the NHC-catalyzed
Bis(amino)cyclopropenylidenes as Organocatalysts for Acyl Anion and Extended Umpolung Reactions
作者:Myron M. D. Wilde、Michel Gravel
DOI:10.1002/anie.201307167
日期:2013.11.25
Back to BACs: In the pursuit of novel carbene organocatalysts, bis(amino)cyclopropenylidenes (BACs) were explored as alternatives to N‐heterocyclic carbenes. They were effective in catalyzing the Stetter reaction, and displayed unique advantages over the commonly used thiazolylidenes and triazolylidenes. They also mediated extendedumpolungreactions of enals. In addition, chiral analogues can be accessed
The construction of 1,2,3-trisubstituted indane rings by the Michael addition of a glycinate followed by an intramolecular Michael cyclization is reported. The tandem process affords indanylglycine derivatives with high regio- and diastereoselectivity.