镍催化与环二磷氮烷或 VAPOL 衍生的亚磷酰胺配体结合,通过二烯醇醚和醛的还原偶联提供对单保护的邻二醇的选择性访问。观察到的区域选择性是前所未有的,因为二烯在亲核性最低且受阻最大的 C 原子上反应,该 C 原子连接到氧取代基而不是在末端位置。值得注意的是,产品的顺式和反式非对映异构体都可以根据二烯伙伴的配置获得,通常具有出色的非对映选择性和对映选择性。
Ni(acac)(2) catalyzes homoallylation of aldehydes with 1,3-dienes in the presence of triethylborane. Triethylborane serves as a reducing agent delivering a formal hydride to the C2 position of 1,3-dienes, thus generating a formal homoallyl anion species and enabling the novelhomoallylation of aldehydes. The reaction proceeds smoothly at room temperature in the absence of any phosphane or nitrogen
Nickel-Catalyzed Enantioselective Synthesis of Pre-Differentiated Homoallylic <i>syn</i>- or <i>anti</i>-1,2-Diols from Aldehydes and Dienol Ethers
作者:Thomas Q. Davies、John J. Murphy、Maxime Dousset、Alois Fürstner
DOI:10.1021/jacs.1c07042
日期:2021.9.1
Nickelcatalysis allied with cyclodiphosphazane or VAPOL-derived phosphoramidite ligands provides selective access to monoprotected vicinal diols by reductive coupling of dienol ethers and aldehydes. The observed regioselectivity is unprecedented, in that the diene reacts at the least nucleophilic and most hindered C atom that is attached to the oxygen substituent rather than at the terminal position
镍催化与环二磷氮烷或 VAPOL 衍生的亚磷酰胺配体结合,通过二烯醇醚和醛的还原偶联提供对单保护的邻二醇的选择性访问。观察到的区域选择性是前所未有的,因为二烯在亲核性最低且受阻最大的 C 原子上反应,该 C 原子连接到氧取代基而不是在末端位置。值得注意的是,产品的顺式和反式非对映异构体都可以根据二烯伙伴的配置获得,通常具有出色的非对映选择性和对映选择性。