Direct, Redox-Neutral Prenylation and Geranylation of Secondary Carbinol C–H Bonds: C4-Regioselectivity in Ruthenium-Catalyzed C–C Couplings of Dienes to α-Hydroxy Esters
作者:Joyce C. Leung、Laina M. Geary、Te-Yu Chen、Jason R. Zbieg、Michael J. Krische
DOI:10.1021/ja3075049
日期:2012.9.26
aryl-substituted α-hydroxy esters to isoprene and myrcene at the diene C4-position, resulting in direct carbinol C-H prenylation and geranylation, respectively. This process enables direct conversion of secondary to tertiary alcohols in the absence of stoichiometric byproducts or premetalated reagents, and is the first example of C4-regioselectivity in catalytic C-C couplings of 2-substituted dienes to carbonyl
由 Ru(3)(CO)(12) 和三环己基膦 PCy(3) 原位生成的钌催化剂促进芳基取代的 α-羟基酯在二烯 C4 位上与异戊二烯和月桂烯发生氧化还原中性 CC 偶联,分别产生直接的甲醇CH异戊二烯化和香叶基化。该过程能够在不存在化学计量副产物或预金属化试剂的情况下将仲醇直接转化为叔醇,并且是2-取代二烯与羰基伴侣的催化CC偶联中C4-区域选择性的第一个例子。机理研究证实了涉及二烯-羰基氧化偶联的催化循环。