O-Protecting groups as long-range stereocontrolling elements in the addition of acetylides to 4-substituted quinolines
摘要:
Addition of magnesium acetylides in the presence of chloroformate esters to racemic differently O-protected 2-(4-quinolyl)propanols and to enantiopure 2-(4-quinolyl)-1,3-dialkoxypropanes, prepared by a chemoenzymatic route, gives almost exclusive regioselective attack at C-2, with stereoselectivities from moderate to good, depending mainly on the bulkiness of the O-protecting group present. (C) 2002 Elsevier Science Ltd. All rights reserved.
Remote control by protecting groups in the diastereoselective addition of acetylides to 2-(4-quinolyl)propanol
作者:Giuseppe Guanti、Sara Perrozzi、Renata Riva
DOI:10.1016/s0957-4166(98)00418-2
日期:1998.11
Differently O-protected 2-(4-quinolyl)propanols undergo, in the presence of chloroformate esters, a regio- and stereoselective addition of acetylides on the carbon alpha to nitrogen with moderate to good diastereoselectivity. The bulkiness of the OH protecting group, which has a 1,7 relationship with the newly created stereocentre, appears to be mainly responsible for this remote stereocontrol. (C) 1998 Elsevier Science Ltd. All rights reserved.