1-Alkynyl Grignard reagents react with (SS)-(−)-menthyl p-toluenesulfinate in toluene to give optically active 1-alkynylp-tolylsulfoxides in high yields. The 1-alkynylsulfoxides thus obtained undergo a stereoselective hydroalumination followed by hydrolysis to afford the corresponding (E)-1-alkenylp-tolylsulfoxides with high optical purity.
Stereodivergent synthesis of 1,4-dicarbonyls by traceless charge–accelerated sulfonium rearrangement
作者:Dainis Kaldre、Immo Klose、Nuno Maulide
DOI:10.1126/science.aat5883
日期:2018.8.17
are four possible mutual geometries, all with potentially distinct biochemical properties. Kaldre et al. present a single method to access each stereoisomer individually. The outcome depends on the straightforwardly tunable configuration of a sulfoxide group in a precursor, which guides a rearrangement. The versatility of the method should facilitate selective access to 1,4-dicarbonyl motifs in pharmaceutical
On treatment with pyridine–camphorsulphonic acid, (S)-E-α-p-tolysulphinyl-α-β-enoates (4) undergo enantio-selectively a sequential prototropic shift and allylic sulphoxide–sulphenate rearrangement to produce (R)-E-γ-hydroxy-α,β-enoates (2) in 64–72% optical purity.
Stereoselective Hydrocyanation of Alkenyl Sulfoxides as a Method to Highly Enantiomerically Enriched Compounds with Tertiary and Quaternary Chiral Carbon Atoms
作者:Jose L. García Ruano、Marta Cifuentes García、Nieves M. Laso、Ana M. Martín Castro、Jesús H. Rodríguez Ramos
Terminal alkynes are easily transformed into enantiomerically enriched compoundscontaining tertiary and quaternarycarbonatoms. Sulfinylation followed by reduction (or alkylation) and hydrocyanation of the resulting vinyl sulfoxides with Et2 AlCN provides nitriles bearing the chiral center, which can in turn undergo reaction to form the desired products. Tol=4-tolyl.
Sulfoxide-controlled SN2′ displacements between cyanocuprates and epoxy vinyl sulfoxides
作者:Joseph P. Marino、Laura J. Anna、Roberto Fernández de la Pradilla、María Victoria Martínez、Carlos Montero、Alma Viso
DOI:10.1016/0040-4039(96)01817-5
日期:1996.10
Readily available enantiomerically pure epoxy vinyl sulfoxides 10–13 and 15 undergo highly regio-and stereoselective SN2′ displacements with alkyl cyanocuprates. The sulfinyl auxiliary controls the anti-syn stereochemistry of the process.
现成的对映体纯净的环氧乙烯基亚砜10-13和15与氰基氰酸烷基酯发生高度区域和立体选择性的S N 2'置换。亚磺酰基助剂控制该过程的反合成立体化学。