Arynes, generated in situ from ortho-silylaryl triflates, undergo ene reaction with alkynes possessing propargylic hydrogen in the presence of KF/18-crown-6 in THF at room temperature to give substituted phenylallenes. Various terminal and internal alkynes as well as different arynes can be used to give the corresponding phenylallenes in good to moderate yields. The reaction of alkyne without propargylic
allenylation, allylation, and annulation reactions. The outcome is governed by both the reactivity of the allene and the formation and stability of the organometallic intermediate. An efficient Rh(III)-catalyzed, weakly coordinating group-directed dienylation of electronically unbiased allenes is developed using an N-acyl amino acid as a ligand. Further elaboration of the dienylated products to construct
Ligand‐Controlled Regiodivergent Cyanoboration of Internal Allenes by Copper Catalysis
作者:Hui Hu、Guo‐Cui Ji、Linjuan Jiang、Siwei Bi、Yuan‐Ye Jiang、Yuanhong Liu
DOI:10.1002/anie.202210338
日期:2022.12.19
The first copper-catalyzed regiodivergent cyanoboration of internal allenes with B2pin2 and NCTS derivatives has been developed. MeOH was identified as the necessary additive for the regeneration of LCu-Bpin species. Computational studies revealed that the copper-mediated allylic cyanation is the regio- and stereo-determining step, while the MeOH-assisted transmetalation with B2pin2 is the rate-determining
已经开发出第一个铜催化的具有 B 2引脚2和 NCTS 衍生物的内部丙二烯区域发散氰基硼化反应。MeOH 被确定为 LCu-Bpin 物种再生的必要添加剂。计算研究表明,铜介导的烯丙基氰化作用是区域和立体决定步骤,而甲醇辅助的 B 2 pin 2金属转移是速率决定步骤。