C–H Alkenylation of Heteroarenes: Mechanism, Rate, and Selectivity Changes Enabled by Thioether Ligands
作者:Bradley J. Gorsline、Long Wang、Peng Ren、Brad P. Carrow
DOI:10.1021/jacs.7b03887
日期:2017.7.19
catalytic intermediate in these reactions may also account for unusual catalyst-controlled site selectivity wherein C–H alkenylation of five-atom heteroarenes can occur under electronic control with thioether ligands even when this necessarily involves reaction at a more hindered C–H bond. The thioether effect also enables short reaction times under mild conditions for many O-, S-, and N-heteroarenes (55 examples)
N-methylation of sulfoximines using methylboronic acid is reported. The reactions provide excellent yields in a short span of time under mild conditions. The optimized conditions were also found to be suitable for the N-alkylation of sulfoximine with different alkylboronic acids. In addition, N-methylation and cyclopropylation of the bioactive L-methionine sulfoximine derivative was demonstrated under standard
A Mild, Chemoselective Oxidation of Sulfides to Sulfoxides Using <i>o-</i>Iodoxybenzoic Acid and Tetraethylammonium Bromide as Catalyst
作者:Vidyanand G. Shukla、Paresh D. Salgaonkar、Krishnacharya G. Akamanchi
DOI:10.1021/jo034483b
日期:2003.6.1
A mild, selective, and high-yielding method for oxidation of sulfides to sulfoxides using IBX and tetraethylammonium bromide in a variety of solvents is described. The method offers the advantage of short reaction times, no over-oxidation to sulfones, and compatibility to a wide range of functional groups.
β-heteroatoms substituted ethyl phenylsulfoxides was carried out using 1-chloroethyl phenylsulfoxide (1); two diastereomeric 1-acetoxyethyl (substituted phenyl) sulfoxides (2a) and (2b); and 2-chloroethyl phenyl, 2-bromoethyl phenyl, and 2-methoxyethyl phenylsulfoxides (3, 4, 5). The rate of pyrolysis of 1 was 4.8 times faster at 160°C than that of ethyl phenylsulfoxide used as a reference, while those
A mild and chemoselective CALB biocatalysed synthesis of sulfoxides exploiting the dual role of AcOEt as solvent and reagent
作者:Silvia Anselmi、Siyu Liu、Seong-Heun Kim、Sarah M. Barry、Thomas S. Moody、Daniele Castagnolo
DOI:10.1039/d0ob01966f
日期:——
Sulfoxides have been synthesised from various sulfide substrates under mild conditions exploiting CALB biocatalyst in the presence of urea hydrogen peroxide and AcOEt which acts with the dual role of solvent and reagent.