Investigation of steric and electronic effects in the copper-catalysed asymmetric oxidation of sulfides
作者:Graham E. O'Mahony、Kevin S. Eccles、Robin E. Morrison、Alan Ford、Simon E. Lawrence、Anita R. Maguire
DOI:10.1016/j.tet.2013.08.063
日期:2013.11
in the copper-catalysed asymmetricoxidation of aryl benzyl, aryl alkyl and alkyl benzyl sulfides have been investigated. The presence of an aryl group directly attached to the sulfur is essential to afford sulfoxides with high enantioselectivities, with up to 97% ee for 2-naphthyl benzyl sulfoxide, the highest enantioselectivity achieved to date for copper-catalysed asymmetric sulfoxidation. In contrast
A comparative study of Cu(II)-assisted vs Cu(II)-free chalcogenation on benzyl and 2°/3°-cycloalkyl moieties
作者:SANTOSH K SAHOO
DOI:10.1007/s12039-015-0981-0
日期:2015.12
A relative synthetic strategy toward intermolecular oxidative C −Chalcogen bond formation of alkanes has been illustrated using both Cu(II) assisted vs Cu(II) free conditions. This led to construction of a comparative study of hydrocarbon benzylic and 2∘/ 3∘-cycloalkyl moieties bond sulfenylation and selenation protocol by the chalcogen sources, particularly sulfur and selenium, respectively. In addition, this protocol disclosed the auspicious formation of sp3 C−S coupling products over leading the sp3 C−N coupling products by using 2-mercaptobenzothiazole (MBT) substrates.
An operationally simple EosinYcatalyzed sulfenylation of hydrazones has been realized to afford a range of thioethers under visible light. The methodology provides high yields of thioethers under ambient conditions employing readily available and inexpensive starting materials. The reaction has broad substrate scope and is compatible with various functional groups.
The bimetallic reagent Sn(II)/Cu(II) in [bmim]BF4 was efficiently used for the cleavage of diaryldiselenides and disulfides and reacts with a variety of organic substrates, such as organic halides, acid chlorides, and β-amino mesylates affording the diorganyl selenides and sulfides within very short reaction times, under mild conditions and with excellent yields, using BMIM-BF4 as a reusable solvent