Conversion of vinyl sulfones to regiospecifically functionalized trisubstituted olefins
摘要:
Conjugate-addition of phenyldimethylsilyllilthium (or cuprate) to vinyl sulfones followed by in situ alkylation of the alpha-sulfonyl anion provides alpha-alkylated beta-silyl sulfones. Treatment of these materials with fluoride provides trisubstituted olefins via the Kocienski olefin synthesis.
possibility of construction of C–C bond via C–N and C–O cleavage. A number of reactions between benzyl ammoniums and vinyl acetates, aryl ammoniums and vinyl acetates, and benzyl ammoniums and aryl C–O electrophiles have been studied. We also disclosed that benzyl ammonium salts can be activated by low-valent nickel to be radicals. 1 Introduction 2 Cross-Coupling of C–N and C–O Electrophiles 3 Summary
Bencyclane fumarate (I) was decomposed in aqueous buffer solution from pH 1.2 to 6.3 in order to examine its stability and mechanism of hydrolysis. It was found that I was hydrolyzed with pseudo first-order kinetics, and the pH-rate profile was a straight line of slope-1. The activation energy (Ea) was calculated to be 33.0 kcal/mol from Arrhenius plots. Further examination of the decomposition mechanism through kinetic analysis suggested a new pathway where I first formed a carbonium ion intermediate in an acidic solution then decomposed immediately into an alcohol and two olefins by hydration and dehydration, respectively.
many strained organic molecules renders them challenging to prepare. Here, we report a strain-inducing positional alkeneisomerization reaction that provides mild and selective access to cyclobutene building blocks from readily obtained cyclobutylidene precursors. This endergonic isomerization relies on the sequential and synergistic action of a decatungstate polyanion photocatalyst and cobaloxime co-catalyst
Conjugate-addition of phenyldimethylsilyllilthium (or cuprate) to vinyl sulfones followed by in situ alkylation of the alpha-sulfonyl anion provides alpha-alkylated beta-silyl sulfones. Treatment of these materials with fluoride provides trisubstituted olefins via the Kocienski olefin synthesis.