Synthesis of α-Hydroxyallenes by Copper-Catalyzed S<sub>N</sub>2′ Substitution of Propargylic Dioxolanones
作者:Xiaoping Tang、Simon Woodward、Norbert Krause
DOI:10.1002/ejoc.200900226
日期:2009.6
catalytic method for the synthesis of α-hydroxyallenes is described. Efficient SN2′ substitution of propargylic dioxolanones has been achieved with a copper(I)/P(OBu)3 catalyst using Grignardreagents as the nucleophiles. The reaction tolerates a wide variety of propargylic dioxolanones, the corresponding primary and secondary α-hydroxyallenes are obtained in good to excellent yields and excellent diastereoselectivity
Enantioselective [3 + 2] Cycloaddition Reaction of Ethynylethylene Carbonates with Malononitrile Enabled by Organo/Metal Cooperative Catalysis
作者:Yu-Chen Zhang、Bo-Wen Zhang、Rui-Long Geng、Jin Song
DOI:10.1021/acs.orglett.8b03454
日期:2018.12.21
The first catalytic asymmetric decarboxylative [3 + 2] cycloaddition reaction of ethynylethylene carbonates with malononitrile has been developed successfully by an organo/copper cooperative system. This strategy led to a series of optically active polysubstituted dihydrofurans in good yields with high levels of enantioselectivities (up to 99% yield, 97% ee). The presence of the terminal alkynyl and
Substrate-Dependent Denitrogenative Rearrangements of Rhodium Azavinyl Carbenes Involving 1,2-Aryl Migration
作者:Geetanjali S. Sontakke、Kuntal Pal、Chandra M. R. Volla
DOI:10.1021/acs.orglett.2c03538
日期:2022.12.9
Herein, we disclose substrate-dependent rearrangements of 4-substituted N-sulfonyl-1,2,3-triazoles under Rh(II)-catalysis via denitrogenation. The reaction pathways included key 1,2-aryl migration via the formation of intermediatory phenonium ion, which is elusive so far with Rh-azavinyl carbenes. Intriguingly, the transformations were completely dependent on the substituent present leading to different
Cp
<sup>X</sup>
Co(III)‐catalyzed selective C–H alkenylation of indoles with ethynylethylene carbonates
作者:Ruihan Niu、Jiakai Zhao、Qi Mou、Ruyuan Zhao、Jing Zhang、Meiqi Wang、Bo Sun
DOI:10.1002/aoc.6863
日期:2022.11
An efficient and selective insertion of indoles into ethynylethylenecarbonates has been achieved via CpXCo(III)-catalyzed C–H functionalization. Compared with a Cp*Co(III) catalyst, the more sterically hindered CpXCo(III) improved the selectivity of rare 1,2-insertion. This protocol provides an approach for synthesizing various vinylindoles in good yields with high regioselectivity.
通过 Cp X Co(III) 催化的 C-H 官能化实现了吲哚有效和选择性地插入到碳酸乙炔基乙烯酯中。与 Cp*Co(III) 催化剂相比,空间位阻更大的 Cp X Co(III) 提高了稀有 1,2-插入的选择性。该协议提供了一种以高区域选择性合成各种乙烯基吲哚的方法。
Cu-catalyzed three-component C S P coupling for the synthesis of trisubstituted allenyl phosphorothioates
cyclic carbonates, elemental sulfur, and H-phosphonates is presented. It proceeds with excellent yields and provides an attractive approach for the construction of valuable trisubstituted allenyl phosphorothioates using a one-step strategy. Moreover, this method can be easily adapted to large-scale preparation.