Multifunctional 1,3-diphenylguanidine for the carboxylative cyclization of homopropargyl amines with CO<sub>2</sub> under ambient temperature and pressure
could be utilized for the carboxylative cyclization of homopropargyl amines with CO2 under ambient temperature and pressure, in combination with AgSbF6, which enabled the synthesis of both chiral and achiral 2-oxazinones efficiently. A mechanistic study revealed that the multi-functionality of DPG is critical to the success of the reaction.
Unprecedented cooperative DBU-CuCl2 catalysis for the incorporation of carbon dioxide into homopropargylic amines leading to 6-methylene-1,3-oxazin-2-ones
作者:Raffaella Mancuso、Ida Ziccarelli、Christian S. Pomelli、Corrado Cuocci、Nicola Della Ca'、Diego Olivieri、Carla Carfagna、Bartolo Gabriele
DOI:10.1016/j.jcat.2020.03.033
日期:2020.7
catalysis by DBU and CuCl2, which allows the carboxylation of homopropargylic amines to high value added 6-methylene-1,3-oxazin-2-ones. This reaction also represents the first efficient method for the catalytic incorporation of CO2 into an acyclic substrate to give oxazinones. DFT calculations are in agreement with a mechanism involving: a) deprotonation of the substrate by DBU; b) CO2 capture with
The reaction of 3-aminoalkynes 2 with carbon monoxide and selenium yielded 5-alkylideneselenazolin-2-ones 3 stereoselectively via cycloaddition of in situ generated carbamoselenoates to the carbon-carbon triple bond. 4-Aminoalkyne 7 also afforded the corresponding six-membered selenium-containing heterocycle with the aid of CuI.