Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, United States.
J Am Chem Soc. 2012 Sep 26;134(38):15700-3. doi: 10.1021/ja3075049. Epub 2012 Sep 17.
The ruthenium catalyst generated in situ from Ru(3)(CO)(12) and tricyclohexylphosphine, PCy(3), promotes the redox-neutral C-C coupling of 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 partners. Mechanistic studies corroborate a catalytic cycle involving diene-carbonyl oxidative coupling.
由 Ru(3)(CO)(12) 和三环己基膦（PCy(3)）原位生成的钌催化剂促进了取代芳基α-羟基酯与异戊二烯和桃金娘烯的氧化还原中性 C-C 偶联，分别在双键 C4-位形成直接的醇碳氢键烯丙基化和香叶基化。该过程可在没有化学计量的副产物或预金属化试剂的情况下，将仲醇直接转化为叔醇，并且是首例催化 2-取代二烯与羰基偶联物的 C4-区域选择性的例子。机理研究证实了一个涉及二烯-羰基氧化偶联的催化循环。
