Copper-catalyzed Pummerer type reaction of α -thio aryl/heteroarylacetates: Synthesis of aryl/heteroaryl α -keto esters
作者:Pipas Saha、Sumit Kumar Ray、Vinod K. Singh
DOI:10.1016/j.tetlet.2017.03.069
日期:2017.5
A copper catalyzed Pummerer type reaction of α-thio aryl/heteroarylacetates is described for the first time. This transformation represents a new route to synthesize α-keto esters, which are important intermediates for pharmaceuticals and organic synthesis. The reaction proceeds via in situ generation of a thionium ion that undergoes hydrolysis to furnish α-keto esters in synthetically viable yields
Fe(OTf)2 was used to catalyze the insertionreaction of α-diazocarbonyls into S–H bonds at 40 °C. A wide range of α-thioesters were obtained in yields up to 96% within 24–48 h from their corresponding α-diazoesters. A variety of thiols were used for the unprecedented insertionreaction with an α-diazoketone, leading to yields up to 85% of α-thioketones.
Pd-Catalyzed Decarboxylative Olefination: Stereoselective Synthesis of Polysubstituted Butadienes and Macrocyclic P-glycoprotein Inhibitors
作者:Bichao Song、Peipei Xie、Yingzi Li、Jiping Hao、Lu Wang、Xiangyang Chen、Zhongliang Xu、Haitian Quan、Liguang Lou、Yuanzhi Xia、K. N. Houk、Weibo Yang
DOI:10.1021/jacs.0c00078
日期:2020.6.3
The efficient and stereoselective synthesis of polysubstituted butadienes, especially the multifunctional butadiene, represents a great challenge in organic synthesis. Herein, we wish to report a distinctive Pd(0) car-bene-initiated decarboxylative olefination approach that enables the direct coupling of diazo esters with vinylethylene carbonates (VECs), vinyl oxazolidinones, or vinyl benzoxazinones
Blue Light-Emitting Diode-Mediated <i>In Situ</i> Generation of Pyridinium and Isoquinolinium Ylides from Aryl Diazoesters: Their Application in the Synthesis of Diverse Dihydroindolizine
作者:Saibal Sar、Souvik Guha、Tejas Prabakar、Debajit Maiti、Subhabrata Sen
DOI:10.1021/acs.joc.1c01209
日期:2021.9.3
1/2, aryl diazoesters 3, and acrylic ester/3-alkenyl oxindoles 5/6 provide various dihydroindolizines 7 to 9 in excellent yield. The principle of the strategy is photolytic generation of nitrogen ylidesfrom N-heteroarenes and aryl diazoesters and their subsequent [3 + 2] cycloaddition reaction with dipolarophiles. Detailed mechanistic analysis of the transformation through control experiments establishes
An efficient copper-catalyzedcarbenoidinsertion reaction of α-diazo carbonyl compounds into Si–H and S–H bonds was developed. A wide range of α-silylesters and α-thioesters was obtained in high yields (up to 98%) from α-diazoesters using 5 mol% of a simple copper(I) salt as catalyst. Using 0.05 mol% of the same catalyst, α-diazoketones led to α-silylketones in low to good yields (up to 70%).