Stereoselective Synthesis of Exocyclic Tetrasubstituted Vinyl Halides via Ru-Catalyzed Halotropic Cycloisomerization of 1,6-Haloenynes
作者:Barry M. Trost、Christopher A. Kalnmals
DOI:10.1021/acs.orglett.7b00879
日期:2017.5.5
Herein, a ruthenium-catalyzed cycloisomerization that transforms 1,6-haloenynes into 5-membered carbo- and heterocycles that bear exocyclic, stereodefined, tetrasubstituted vinylhalides is reported. The reaction is insensitive to air and water, tolerates a variety of functional groups, and proceeds with good to excellent stereoselectivity and yield.
Bicyclo under construction! The [RhCl(dppp)2]‐catalyzed intramolecular [6+2] cycloisomerization of alkyne–allenylcyclobutanes efficiently produced bicyclo[6.4.0]dodecatriene and bicyclo[6.3.0]undecatriene skeletons (see scheme). Straightforward cleavage of the unfunctionalized simple cyclobutane and construction of the bicyclo[6.m.0] frameworks could be achieved under mild conditions.
Iron-catalyzed [2 + 2 + 2] cycloaddition reactions of diynes with siloxyphosphaethynes have been developed to give 2-phosphaphenol derivatives. The use of electronically neutral siloxyphosphaethynes generated in situ by the reaction of anionic phosphaethynolate with silyl triflates is key to achieving the reactions.