Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371.
Org Lett. 2010 Sep 17;12(18):4180-3. doi: 10.1021/ol101777x.
A ternary catalytic system consisting of a cobalt salt, a diphosphine ligand, and a Grignard reagent promotes syn-addition of an azole C(2)-H bond across an unactivated internal alkyne with high chemo-, regio-, and stereoselectivities under mild conditions. Mechanistic experiments suggest that the reaction involves oxidative addition of the oxazolyl C-H bond to the cobalt center, alkyne insertion into the Co-H bond, and reductive elimination of the resulting diorganocobalt species.
一个由钴盐、双膦配体和格氏试剂组成的三元催化体系在温和条件下高化学选择性、区域选择性和立体选择性地促进唑 C(2)-H 键与未活化的内部炔烃的顺式加成。机理实验表明，反应涉及唑基 C-H 键向钴中心的氧化加成、炔烃插入 Co-H 键以及生成的二有机钴物种的还原消除。
