AbstractOptically active β‐hydroxy sulfonamides and β‐hydroxy sulfones are very important building blocks for the preparation of bioactive compounds and pharmaceuticals. In this work, a highly efficient asymmetric hydrogenation of β‐keto sulfonamides and β‐keto sulfones has been developed using the phosphine‐free chiral ruthenium complex Ru(OTf)(TsDPEN)(η6‐p‐cymene) as the catalyst, to afford the corresponding β‐hydroxy sulfonamides and β‐hydroxy sulfones in high yields with excellent optical purities. In addition, a cascade asymmetric hydrogenation/dynamic kinetic resolution (DKR) of racemic cyclic β‐keto sulfonamides and β‐keto sulfones was also realized using the same catalyst, to give the corresponding chiral cyclic β‐hydroxy sulfonamides and β‐hydroxy sulfones in good yields with excellent enantio‐ and diastereoselectivities.magnified image
Synthesis and reactivity of N-alkyl-2-oxoalkanesulfonamides
作者:Juan A. Vega、Ramón Alajarín、Juan J. Vaquero、Julio Alvarez-Builla
DOI:10.1016/s0040-4020(98)00093-3
日期:1998.4
A series of N-alkyl-2-oxoalkanesulfonamides have been synthesized by reacting silyl enol ethers with N-alkyl-sulfamoyl chlorides. Their reactivity towards electrophiles was investigated in order to explore the regio-and stereoselectivity of the process. 2-Oxoalkanesulfonamides were used to prepare 5-(methylsulfamoyl)-1,4-dihydropyridines derivatives. (C) 1998 Elsevier Science Ltd. All rights reserved.