An unprecedented stereoselective base-induced trimerization of an α-bromovinylsulfone
A unprecedented base-induced trimerization of bromovinylsulfone 1 afforded the cyclohexene 6 as a single diastereoisomer. Optimization of this reaction gave the adduct 6 in 49% yield. A mechanistic rationale for the trimerization involving consecutive SN2′ additions and [3,3]-rearrangements and a final stereoselective intramolecular conjugate addition is proposed and supported by M06-2X density functional theory calculations.
Fisher, Brendan,Lepage, Romain J.,White, Jonathan M.,Ye, Young,Krenske, Elizabeth H.,Rizzacasa, Mark A.
p. 5529 - 5534
(2017/07/12)
A New Method for the Synthesis of α-Bromoacyl Silanes via Ring-opening of 2-Phenylsulphonyl-2-trimethylsilyloxiranes
2-Phenylsulphonyl-2-trimethylsilyloxiranes 2 are efficiently prepared by treatment of 2-phenyl-sulphonyloxiranes 3 with butyllithium in the presence of chlorotrimethylsilane at low temperatures.Reaction of 3-alkyl-2-phenylsulphonyl-2-trimethylsilyloxiranes 2, in which the alkyl group is primary, with magnesium bromide at room temperature gives 2-bromoacyl silanes 1 in good yield.Reaction at higher temperatures leads to competing formation of bromovinyl sulphones 7.Reaction of 3,3-dialkyloxiranes with magnesium bromide occurs much more readily, leading to 2-bromoacyl silanes 1 in moderate yields.Other products derived from a common carbocationic intermediate are also isolated.
Hewkin, Cheryl T.,Jackson, Richard F. W.
p. 3103 - 3112
(2007/10/02)
More Articles about upstream products of 54897-43-7