A new Cp*Rh(III)-catalyzed regioselective cyclization reaction of aromatic amides with allenes is reported. The use of allenyl derivatives bearing a directing-group assistant as a reaction promoter was the key to the success of this protocol. In this catalytic system, N-(pivaloyloxy)benzamide substrates react with allenes via Rh–σ–alkenyl intermediates, while N-(pivaloyloxy) indol substrates react
报道了一种新的 Cp*Rh( III ) 催化的芳香酰胺与丙二烯的区域选择性环化反应。使用带有导向基助剂的丙二烯基衍生物作为反应促进剂是该方案成功的关键。在该催化体系中, N- (新戊酰氧基)苯甲酰胺底物通过Rh-σ-烯基中间体与丙二烯反应,而N- (新戊酰氧基)吲哚底物通过Rh-π-烯丙基中间体反应。这些反应具有反应条件温和、底物范围广、官能团相容性高等特点,得到了多种高价值的异喹啉酮和嘧啶并[1,6- a ]吲哚-1( 2H )-1骨架化合物。还研究了合成应用和主要机制。
Organophosphine as an Alkyl Transfer Shuttle for the Direct β-Alkylation of Chalcones Using Alkyl Halides
作者:Li-Jie Gu、Chao-Yang Li、Xin-Yue Niu、Xiong-Li Liu、Zhan-Wei Bu、Qi-Lin Wang
DOI:10.1021/acs.joc.2c02505
日期:2023.1.6
this transformation, the ortho-phosphanyl substituent in the chalcones is crucial for controlling their reactivity and selectivity. It also serves as a reliable alkyl transfer shuttle to transform electrophilic alkyl bromides into nucleophilic alkyl species in the form of quaternary phosphonium salts and transfer the alkyl group effectively to the β-position of the chalcones. This alkyl transfer strategy
C‐H Functionalization of Heterocycles with Triplet Carbenes by means of an Unexpected 1,2‐Alkyl Radical Migration
作者:Claire Empel、Sripati Jana、Łukasz Ciszewski、Katarzyna Zawada、Chao Pei、Dorota Gryko、Rene M. Koenigs
DOI:10.1002/chem.202300214
日期:——
A tripletcarbene is involved in the C3-H functionalization of indole heterocycles. We herein describe a combined experimental and computational study on this reaction and unveil an unexpected 1,2-alkyl radicalmigration pathway.