Gold-Catalyzed Hydrosilyloxylation Driving Tandem Aldol and Mannich Reactions
作者:Dongjin Kang、Sangjune Park、Taekyu Ryu、Phil Ho Lee
DOI:10.1021/ol301660f
日期:2012.8.3
an enolate from alkyne in the presence of a carbonyl and imine group was realized, which constructed a variety of structural motifs under exceedingly mild reaction conditions in a tandem process. Reaction driving tandem hydrosilyloxylation/aldol reactions was achieved through the formation of enol silyl ethers catalytically generated in situ from readily available alkynes. These reactions were expanded
unprecedented (SiMOS-Phos) ligand-controlled Rh-catalyzed hydrosilylation of “silicon-centered” racemic hydrosilanes was developed for the highly efficient and enantioselective construction of silicon-stereogenic centers of benzosiloles (up to 96 : 4 er). This achievement was obtained by using an original synthetic strategy involving dynamic kinetic asymmetric transformations.
Polyaromatic Ribbon/Benzofuran Fusion via Consecutive Endo Cyclizations of Enediynes
作者:Philip M. Byers、Julian I. Rashid、Rana K. Mohamed、Igor V. Alabugin
DOI:10.1021/ol302922t
日期:2012.12.7
The Sonogashira/5-endo-dig/6-endo-dig cascade fuses a polycyclic aromatic backbone to the electron-rich furan subunit. The transformation proceeds in modest yields as a one-pot reaction. Efficiency of the full cascade is increased by removal of base prior to the addition of gold catalyst. Under these conditions, conversion to the full cascade products is achieved in nearly quantitative yields without purification of the intermediate products. Extension of the cascade toward triynes opens access to benzofuran-fused chrysene derivatives.