作者:Christoph Schneider、Markus Hansch、Timo Weide
DOI:10.1002/chem.200400951
日期:2005.1
Evaluation of a broad range of metal alkoxides as catalysts and optimization of the reaction protocol led to a modified zirconium alkoxide catalyst with attenuated Lewis acidity and dichloromethane as solvent, which resulted in suppression of the undesired acyl migration to a large extent. Various ketone aldols have been prepared and subjected to the general process, giving rise to a broad range of differently
酮醛醇作为烯醇当量的醛醇-季申科反应已被开发为一种有效的策略,可一步实现差异化的1,3-抗二醇单酯。热力学不稳定的酮醛醇醛容易地逆醛醇化,以原位产生推测的烯醇锆,然后通常以高收率和完全的1,3-抗非对映体进行醛醇-季申科反应。对各种金属醇盐作为催化剂的评估以及对反应方案的优化,导致了一种路易斯酸度降低且二氯甲烷为溶剂的改性醇锆氧化物催化剂,从而在很大程度上抑制了不希望的酰基迁移。制备了各种酮醛醇缩醛并进行了通用工艺,从而产生了范围广泛的不同取代的1,