A new and straightforward protocol for the synthesis of quinoline N‐oxides from the annulation of arylnitrones and alkynes is described. For the first time, a [4+2] cyclization of nitrone and alkynes has been achieved by cobalt catalysis via a nitrone‐assisted dualC–H cleavage under relatively mild conditions.
Catalytic Alkyne Arylation Using Traceless Directing Groups
作者:Jung‐Woo Park、Bubwoong Kang、Vy M. Dong
DOI:10.1002/anie.201804955
日期:2018.10.8
to generate enamines, which are then hydrolyzed to either α‐arylphenones or α,α‐diarylketones. This Pd‐catalyzed method overcomes established known pathways to enable the use of amines as tracelessdirectinggroups for C−C bond formation.
Copper-Catalyzed Regioselective Reaction of Internal Alkynes and Diaryliodonium Salts
作者:Ze-Feng Xu、Chen-Xin Cai、Jin-Tao Liu
DOI:10.1021/ol4003543
日期:2013.5.3
The copper-catalyzed highly regioselective reaction of internal alkynes with diaryliodonium salts was achieved for the first time. α-Arylketones were obtained in moderate to good yields from arylpropargylic alcohols or aryl alkyl alkynes under mild conditions. It was found that the two kinds of substrates underwent two different arylation–oxygenation pathways under different reaction conditions based
Enantioselective Resolution Copolymerization of Racemic 2,
<scp>
3‐Disubstituted
<i>cis</i>
‐Epoxides
</scp>
with
<scp>
CO
<sub>2</sub>
</scp>
Mediated by Binuclear Cobalt(
<scp>III</scp>
) Catalyst
<sup>†</sup>
作者:Yan‐Lan Liu、Guang‐Hui He、Ye Liu、Xiao‐Bing Lu
DOI:10.1002/cjoc.202100252
日期:2021.9
Enantioselective resolution copolymerization of racemic internal epoxides with carbon dioxide (CO2) is a challenging issue because of their poor reactivity and complicated regio/stereoselectivity. Herein, we describe the first enantioselective resolution copolymerization of racemic aromatic 2,3-disubstituted cis-epoxides and CO2 using enantiopure dinuclearcobalt(III) complexes as catalyst under mild
外消旋内环氧化物与二氧化碳 (CO 2 ) 的对映选择性拆分共聚是一个具有挑战性的问题,因为它们的反应性差且区域/立体选择性复杂。在此,我们描述了在温和条件下使用对映纯双核钴 (III) 配合物作为催化剂,外消旋芳族 2,3-二取代顺式环氧化物和 CO 2的首次对映选择性拆分共聚,得到了相应的具有完全交替结构和良好对映选择性的聚碳酸酯。 70% 到 97% ee 的范围。β-甲基氧化苯乙烯的全同立构聚碳酸酯是典型的半结晶材料,熔点为 241 oC; 而来自芳环上带有取代基的2,3-二取代顺式环氧化物的其他全同立构浓缩共聚物是无定形的,玻璃化转变温度介于 86 o C 和 124 o C之间。有趣的是,共聚物的选择性与 Hammett 相关性很好取代基常数,并且在使用苯环上带有给电子基团的环氧化物的体系中发现最高的聚合物选择性为 98%。
Direct Synthesis of 1-Arylprop-1-ynes with Calcium Carbide as an Acetylene Source
作者:Lei Gao、Zheng Li
DOI:10.1055/s-0037-1610718
日期:2019.8
A simple method is described for the synthesis of 1-arylprop-1-ynes directly from aromatic aldehyde p-tosylhydrazones by using calcium carbide as an acetylene source. The salient features of this protocol are its use of a readily available and easily handled source of acetylene, its operational simplicity, its high yield, and its broad substrate scope.