Synthesis of Substituted Thioamides from <i>gem</i>
-Dibromoalkenes and Sodiumsulfide
作者:Ashok K. Morri、Yadagiri Thummala、Ramesh Adepu、Gangavaram V. M. Sharma、Subhash Ghosh、Venkata Ramana Doddi
DOI:10.1002/ejoc.201901411
日期:2019.11.14
Synthesis of thioamides from geminal dibromoalkenes, sodium sulfide and formamide have been reported under catalyst or additive free conditions. Control experiment and mechanistic studies revealed that necessary role of sodium sulfide in this overall transformation.
Rapid access to unsymmetrical 1,3-diynes and 2,5-disubstituted thiophenes under ligand and Pd/Ni-free Cu-catalysis
作者:Maddali L. N. Rao、Sk Shamim Islam、Priyabrata Dasgupta
DOI:10.1039/c5ra15705f
日期:——
A Pd/Ni-free copper-catalysed tandem synthesis was realized for rapid access to unsymmetrical 1,3-diynes from 1,1-dibromoalkenes and terminal alkynes. This method was extended to the straightforward synthesis of unsymmetrical 2,5-disubstitutedthiophenes in a one-pot operation.
Nickel-Promoted Highly Regioselective Carboxylation of Aryl Ynol Ether and Its Application to the Synthesis of Chiral β-Aryloxypropionic Acid Derivatives
作者:Nozomi Saito、Zhongdong Sun、Yoshihiro Sato
DOI:10.1002/asia.201403399
日期:2015.5
Nickel(0)‐promoted carboxylation of arylynolether proceeded in a highlyregioselective manner to produce α‐substituted‐β‐aryloxyacrylic acidderivatives. The α‐substituted‐β‐aryloxyacrylic acids were transformed into the corresponding β‐aryloxypropionic acidderivative as an optically active form via rhodium‐catalyzed asymmetric hydrogenation.
Palladium catalyzed hydrogenolysis of 1,1-dibromo-1-alkenes by tributyltin hydride proceeds smoothly to give (Z)-1-bromo-1-alkenes with excellent stereoselectivity in good yields. Dibromomethylenation of aldehydes by a combination of CBr4 and Ph3P in methylene chloride and the successive hydrogenolysis affords (Z)-1-bromo-1-alkenes in one-pot.
作者:Maddali L. N. Rao、Sk Shamim Islam、Priyabrata Dasgupta
DOI:10.1039/d1ob01383a
日期:——
N-alkynylation of electron-withdrawing or protecting group free N-heteroarenes such as indole, carbazole and pyrrole was developed using gem-dibromoalkenes to synthesize ynamines under ligand-free copper-catalyzed domino conditions. The development methodology of ynamines was also applied in the synthesis of enynamines, multi-coupled bis-ynamines, tris-ynamines, and the natural product peyonine, demonstrating