Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China.
Fengxian Hospital, Southern Medical University, 6600 Nanfeng Road, Shanghai 201499, P. R. China.
Org Lett. 2020 Jun 19;22(12):4680-4685. doi: 10.1021/acs.orglett.0c01483. Epub 2020 Jun 2.
Herein an efficient Pd-catalyzed asymmetric allylic substitution cascade of both ()- and ()-but-2-ene-1,4-diyl dimethyl dicarbonates with α-substituted cyano ketones is described for the preparation of chiral 2,3-dihydrofurans in up to 97% yield with 98% ee. A suggested steric control process has been proposed to illustrate the differences in enantioselectivity between the reactions of ()- and ()-allyl substrates. The cascade reaction could be conducted on a gram-scale, and the resulting product allows for several transformations.
本文描述了一种高效的 Pd 催化的（）-和（）-丁-2-烯-1,4-二基二甲酸二甲酯与α-取代氰基酮的不对称烯丙基取代级联反应，用于制备手性 2,3-二氢呋喃，产率高达 97%，对映选择性为 98%ee。提出了一种空间控制过程来解释（）-和（）-烯丙基底物反应之间的对映选择性差异。该级联反应可以进行克级规模的实验，得到的产物可以进行多种转化。
