Chromium-Catalyzed Regioselective Hydropyridination of Styrenes
作者:Yuexuan Li、Gongda Deng、Xiaoming Zeng
DOI:10.1021/acs.organomet.5b01021
日期:2016.3.14
The first chromium-catalyzed regioselective addition of para-C-H bonds, of pyridines across styrenes is disclosed. The hydrofunctionalization reaction was promoted by a low-cost chromium(III) chloride combining with a cyclohexyl Grignard reagent and 2,2'-bipyridine, which allows for the highly selective formation of branched products via the cleavage of inert C-H bonds Of pyridines.
Cobalt-Catalyzed C4-Selective Direct Alkylation of Pyridines
How pyridine got its tail: A new catalyst for the atom‐economical C4‐selective direct alkylation of pyridines is described. A combination of CoBr2 and LiBEt3H catalyzes the reaction of pyridines with 1‐alkenes at 70 °C to give alkylation products with C4/C2 ratios of >20:1. Substrate/catalyst ratios of up to 4000, and a turnover number of 3440 were achieved.