Transition-Metal Free Chemoselective Hydroxylation and Hydroxylation–Deuteration of Heterobenzylic Methylenes
作者:Yonghai Liu、Yang Yu、Chengyu Sun、Yiwei Fu、Zhiguo Mang、Lei Shi、Hao Li
DOI:10.1021/acs.orglett.0c03108
日期:2020.10.16
We developed an approach for direct selective hydroxylation of heterobenzylic methylenes to secondary alcohols avoiding overoxidation to ketones by using a KOBu-t/DMSO/air system. Most reactions could reach completion in several minutes to give hydroxylated products in 41-76% yields. Using DMSO-d6, this protocol resulted in difunctionalization of heterobenzylic methylenes to afford α-deuterated secondary alcohols (>93% incorporation). By employing this method, active pharmaceutical ingredients carbinoxamine and doxylamine were synthesized in two steps in moderate yields.
Ortho lithiation of 2-, 3-, and 4-methoxypyridines
作者:Daniel L. Comins、Donald H. LaMunyon
DOI:10.1016/s0040-4039(00)80206-3
日期:1988.1
The ortholithiation of 2-,3-, and 4-methoxypyridine was effected using mesityllithium as the metalating base.