NHC-Catalyzed Reaction of Enals with Hydroxy Chalcones: Diastereoselective Synthesis of Functionalized Coumarins
作者:Anup Bhunia、Atanu Patra、Vedavati G. Puranik、Akkattu T. Biju
DOI:10.1021/ol400562z
日期:2013.4.5
The N-heterocyclic carbene-catalyzed annulation of enals with 2′-hydroxy chalcones afford cyclopentane-fused coumarin derivatives with an excellent level of diastereocontrol. The reaction tolerates a broad range of functional groups; 25 examples are given, and a preliminary mechanistic investigation is provided.
A Method for the Analysis of Free Carbenes Present after NHC-Organocatalyzed Transformations
作者:Tamal Kanti Das、Akkattu T. Biju
DOI:10.1002/ejoc.201700903
日期:2017.8.17
A systematic analysis of free N-heterocyclic carbenes (NHCs) present in the reaction flask after NHC-organocatalyzed reactions has been performed by treating the reaction mixture with elemental sulfur and isolating and analyzing the formed thiourea/thione derivatives.