LiBF4: A mild lewis acid for intramolecular diels-alder reactions.
作者:Douglas A. Smith、K.N. Houk
DOI:10.1016/s0040-4039(00)74269-9
日期:1991.3
The lithium salts, LiClO4 and LiBF4, have been investigated for their potential use as Lewis acid catalysts in the intramolecular Diels-Alder reaction. No cycloaddition of the trienone, 1, is observed when LiClO4 is used. LiBF4 provides quantitative yield of the cis-fused cycloadduct in 72 hours at room temperature. The catalysis is ascribed to the slow release of BF3 rather than to the lithium cation
已经研究了锂盐LiClO 4和LiBF 4在分子内Diels-Alder反应中作为路易斯酸催化剂的潜在用途。当使用LiClO 4时,未观察到三烯酮1的环加成。LiBF 4在室温下72小时内可定量提供顺式融合的环加合物。催化作用归因于BF 3的缓慢释放,而不是锂阳离子。