Palladium/H<sup>+</sup>-cocatalyzed kinetic resolution of tertiary propargylic alcohols
作者:Wanli Zhang、Shengming Ma
DOI:10.1039/c8cc01949e
日期:——
A new approach to not-readily-available opticallyactive tertiary propargylic alcohols through palladium/H+-cocatalyzed carboxylation of racemic tertiary propargylic alcohols with CO and MeOH has been described. Bothenantiomers can be obtained with no less than 90% ee utilizing (R) or (S)-DTBM-Segphos. Various transformations of the opticallyactive alcohols have been demonstrated.
已经描述了通过钯/ H + -外消旋的叔炔丙醇与CO和MeOH的羧化羧化反应来制备尚未得到的旋光性叔炔丙醇的新方法。利用(R)或(S)-DTBM-Segphos,两种对映体都可以以不小于90%的ee获得。已经证明了旋光性醇的各种转化。
Lithium Binaphtholate-Catalyzed Asymmetric Addition of Lithium Acetylides to Carbonyl Compounds
The asymmetric addition of lithium acetylides to carbonylcompounds in the presence of a chiral lithium binaphtholate catalyst was developed. A procedure involving the slow addition of carbonylcompounds to lithium acetylides improved the enantioselectivity. This reaction afforded diverse chiral secondary and tertiary propargylic alcohols in high yields and with good to high enantioselectivities.
Chiral lithium binaphtholate effectively catalyzed the enantioselectivealkynylation of ketones using lithium acetylide as an alkynylating agent. This is the first example of the catalytic enantioselective addition of lithium acetylide to carbonyl compounds without the aid of other metal sources.