Abstract A decarboxylative hydroamination cascade reaction of 3-arylpropiolic acids with N-heterocycles under transition-metal-free conditions was developed. 3-Arylpropiolic acids were found to react smoothly with a range of N-heterocycles under the effect of t-BuOK to afford N-vinyl heterocycles in moderate to excellent yields. This reaction represents the first decarboxylative hydroamination of 3-arylpropiolic
Inorganic base-mediated stereoselective hydroamination of arylalkynes with imidazole: An efficient access to N -vinylimidazoles
作者:Lin-Dong Liu、Zhong-Liang Lei、Hong Wang、Ming Bian、Zhen-Jiang Liu、Jin-Tao Liu、Xiao-Jun Hu
DOI:10.1016/j.tet.2018.07.022
日期:2018.8
A metal-free inorganic base-mediated highly stereoselective hydroamination of arylalkynes with imidazoles has been developed, and the corresponding N-vinylimidazoles were obtained in good yields and with moderate to excellent stereoselectivities (up to 99:1). For the electron rich alkynes, the reaction system of CsOH center dot H2O/NMP/140 degrees C led to the predominant formation of E-addition products, while the reaction system of KOH/NMP/90 degrees C afforded the Z-isomers as the major product. The electron deficient alkynes furnished predominantly the E-addition products in both reaction systems. This study essentially provides a general and an efficient protocol for the synthesis of E-isomer of the N-vinylimidazoles. (C) 2018 Elsevier Ltd. All rights reserved.
Palladium-Catalyzed Oxidative Intramolecular CC Bond Formation via Double sp2 CH Activation between the 2-Position of Imidazoles and a Benzene Ring
作者:Manman Sun、Huandong Wu、Junnan Zheng、Weiliang Bao
DOI:10.1002/adsc.201100801
日期:2012.3.16
Oxidative intramolecularCCbond formation via double sp2 CHactivation between the 2‐position of imidazoles and a benzene ring catalyzed by palladium(II) has been developed, which provides an atom‐economical, concise and efficient methodology to synthesize imidazole‐ or benzimidazole‐fused isoquinoline polyheteroaromatic compounds.
Base-catalyzed stereoselective intermolecular addition of imidazoles onto alkynes: an easy access to imidazolyl enamines
作者:Monika Patel、Rakesh K. Saunthawal、Akhilesh K. Verma
DOI:10.1016/j.tetlet.2013.12.100
日期:2014.2
An efficient transition metal-free approach for the regio- and stereoselective addition of imidazoles 1a–f onto alkynes 2a–l to provide the Z- and E isomers of imidazolyl enamines 3a–q and 4a–d using catalytic amount of KOH is described. Stereoselectivity of the addition products (Z and E isomer) was found to be dependent upon time. Competitive experiments show that imidazole is less reactive than