Unusual Highly Regioselective Direct Aldol Additions with a Moisture-Resistant and Highly Efficient Titanium Catalyst
作者:Rainer Mahrwald、Bernd Schetter
DOI:10.1021/ol052637z
日期:2006.1.1
[reaction: see text] The extremely robust and water-stable tetranuclear complex Ti(4)(mu-BINOLato)(6)(mu(3)-OH)(4) was found to catalyze the direct aldol addition with high regioselectivities at the more steric alpha-encumbered side of unsymmetrical ketones. As few as 0.2 mol % loadings with this cluster were enough to afford complete conversions. The reaction proceeds very smoothly without a significant
[反应:见正文]发现极其坚固且水稳定的四核复合物Ti(4)(mu-BINOLato)(6)(mu(3)-OH)(4)催化高羟选择性的直接羟醛加成反应。不对称酮的立体位偏侧。该簇的低至0.2 mol%的负载量足以提供完整的转化率。反应进行得非常顺利,没有大量的副产物。描述了四元立体中心的形成。