Diels−Alder Cycloaddition Strategy for Kinetic Resolution of Chiral Pyrazolidinones
作者:Mukund P. Sibi、Keisuke Kawashima、Levi M. Stanley
DOI:10.1021/ol901504p
日期:2009.9.3
A rare example of the application of a catalytic, enantioselective Diels−Aldercycloaddition to affect a kinetic resolution has been developed. Chiral pyrazolidinones are resolved with high selectivity through a process that utilizes a relay of stereochemical information from a permanent chiral center to a fluxional chiral center to enhance the inherent selectivity of the chiral Lewis acid catalyst
The Meyer-Schuster Rearrangement of Ethoxyalkynyl Carbinols
作者:Gregory Dudley、Susana Lopez、Douglas Engel
DOI:10.1055/s-2007-973885
日期:2007.4
combination of electron-rich alkoxyacetylenes and cationic gold catalysts provides excellent reactivity for the Meyer-Schusterrearrangement under mild conditions. Optimization of the reaction conditions with respect to stereoselectivity and investigations into the scope and mechanism of the rearrangement of secondary ethoxyalkynyl carbinols (y-ethoxy-substituted propargyl alcohols) to α,β-unsaturated esters
Tellurium-zinc exchange reaction. A new preparative method of alkenylzinc reagents
作者:Jun Terao、Nobuaki Kambe、Noboru Sonoda
DOI:10.1016/0040-4039(96)00955-0
日期:1996.7
Alkenyl tellurides were converted to the corresponding alkenylzinc compounds by the reaction with diethylzinc. The exchange reaction proceeds efficiently in THF at room temperature with retention of the stereochemistry of the starting tellurides. The successive reaction of the formed alkenylzinc with 4-iodotoluene in the presence of Pd(PPh3)4 afforded a cross-coupling product as a single stereoisomer
TMSCl-Mediated Catalytic Carbocupration of Alkynoates: An Unprecedented and Remarkable Effect of Catalyst Loading on Highly Selective Stereochemical Induction via a TMS-Allenoate Intermediate
A Convenient Synthesis of 3-Alkyl-4-aminobutanoic Acids
作者:Ryszard Andruszkiewicz、Richard B. Silverman
DOI:10.1055/s-1989-27443
日期:——
A series of 3-alkyl-4-aminobutanoic acids were prepared via the Michael addition of nitromethane to 2-alkenoic esters, followed by catalytic hydrogenation of the resultant 3-(nitromethyl)alkanoic esters using 10% palladium on carbon in acetic acid, and acid hydrolysis of the reduction products.