Metal-free synthesis of imidazole by BF<sub>3</sub>·Et<sub>2</sub>O promoted denitrogenative transannulation of <i>N</i>-sulfonyl-1,2,3-triazole
作者:Dongdong Yang、Lihong Shan、Ze-Feng Xu、Chuan-Ying Li
DOI:10.1039/c8ob00083b
日期:——
BF3·Et2Opromoted metal-free denitrogenative transannulation of N-sulfonyl-1,2,3-triazole was reported. Rather than transition metals, BF3·Et2O was employed for the first time to promote the formation of α-diazoimines from N-sulfonyl-1,2,3-triazoles in nitriles, leading to the synthesis of various imidazoles. The protocol tolerates a broad range of functional groups and could also be applied to the
Copper-Catalyzed Formal Transfer Hydrogenation/Deuteration of Aryl Alkynes
作者:Samantha E. Sloane、Albert Reyes、Zoua Pa Vang、Lingzi Li、Kiera T. Behlow、Joseph R. Clark
DOI:10.1021/acs.orglett.0c03632
日期:2020.11.20
A copper-catalyzed reduction of alkynes to alkanes and deuterated alkanes is described under transfer hydrogenation and transfer deuteration conditions. Commercially available alcohols and silanes are used interchangeably with their deuterated analogues as the hydrogen or deuterium sources. Transfer deuteration of terminal and internal aryl alkynes occurs with high levels of deuterium incorporation
Enantioselective Copper Catalyzed Alkyne–Azide Cycloaddition by Dynamic Kinetic Resolution
作者:En-Chih Liu、Joseph J. Topczewski
DOI:10.1021/jacs.9b01091
日期:2019.4.3
The copper(I) catalyzed alkyne-azide cycloaddition (CuAAC), a click reaction, is one of the most powerful catalytic reactions developed during the last two decades. Conducting CuAAC enantioselectively would add a third dimension to this reaction and would enable the direct synthesis of α-chiral triazoles. Doing so is demanding because the two precursors have linear geometries, and the triazole product
Dioxazoles, a new mild nitrene transfer reagent in gold catalysis: highly efficient synthesis of functionalized oxazoles
作者:Ming Chen、Ning Sun、Haoyi Chen、Yuanhong Liu
DOI:10.1039/c6cc02776h
日期:——
A gold-catalyzed regioselective [3+2] cycloaddition of ynamides with 1,4,2-dioxazoles has been developed, which offers a novel approach to highly functionalized oxazoles under mild reaction conditions. 1,4,2-Dioxazole was found to act...
Thermoneutral synthesis of spiro-1,4-cyclohexadienes by visible-light-driven dearomatization of benzylmalonates
作者:Quan-Qing Zhao、Julia Rehbein、Oliver Reiser
DOI:10.1039/d1gc04686a
日期:——
No preactivation or coupling to high-energy reagents is required for the dearomative coupling of benzylmalonates and acetylenes, although the transformation has no significant thermodynamic driving force.