A facile and practical method for the stereospecific synthesis of α-oxoketene O,S-acetals in water has been developed. Catalyzed by tetrabutylammonium bromide at room temperature, the one-pot reaction of various β-dicarbonyl compounds, 2-bromoethanol, and carbon disulfide, in the presence of potassium carbonate, leads to the corresponding α-oxoketene O,S-acetals stereospecifically in good to excellent
Visible-Light-Induced Formation of Thiavinyl 1,3-Dipoles: A Metal-Free [3+2] Oxidative Cyclization with Alkynes as Easy Access to Thiophenes
作者:Baihui Zheng、Xiaotong Li、Yang Song、Shuyang Meng、Yifei Li、Qun Liu、Ling Pan
DOI:10.1021/acs.orglett.1c00915
日期:2021.5.7
previously unknown thiavinyl 1,3-dipoles in the presence of an acridine photosensitizer is reported. A series of multisubstituted thiophenes were achieved regioselectively in ≤98% yields under very mild metal-free conditions without other additives. This reaction could tolerate a wide range of substrates and achieve good efficiency in large-scale syntheses. The reaction mechanism and their applications