Synthesis of Sulfoxides by the Hydrogen Peroxide Induced Oxidation of Sulfides Catalyzed by Iron Tetrakis(pentafluorophenyl)porphyrin: Scope and Chemoselectivity
The oxidation of sulfides with H2O2 catalyzed by iron tetrakis(pentafluorophenyl)porphyrin in EtOH is an efficient and chemoselective process. With a catalyst concentration 0.03−0.09% of that of the substrate, sulfoxides are obtained with yields generally around 90−95% of isolated product. With vinyl and allyl sulfides, no epoxidation is observed. With a catalyst concentration between 0.09% and 0.25%
四(五氟苯基)卟啉铁在EtOH中催化的H 2 O 2氧化硫化物是一种有效的化学选择过程。在催化剂浓度为底物浓度的0.03-0.09%的情况下,获得的亚砜的收率通常约为分离产物的90-95%。对于乙烯基和烯丙基硫化物,未观察到环氧化。催化剂浓度为底物浓度的0.09%至0.25%,可以以几乎定量的产率获得砜,并且在亚砜的合成中观察到相同的高化学选择性。
Diastereoselectivity in the Preparation of 4-Phenylthio-4-butanolide Derivatives by the Use of the Pummerer Rearrangement
Diastereoselectivity in the preparation of 4-phenylthio-4-butanolide derivatives by the Pummererrearrangement of 4-phenylsulfinylbutanoic acid derivatives was clarified. The reaction of 3-alkyl-4-phenylsulfinylbutanoic acid with acetic anhydride resulted in the predominant formation of trans-3-alkyl-4-phenylthio-4-butanolide. Lactonization of 2,3-dialkyl-4-phenylsulfinylbutanoic acid gave (2RS,3RS
A conjugate addition/sulfoxide elimination route to allylic difluorophosphonates
作者:Kevin Blades、Jonathan M. Percy
DOI:10.1016/s0040-4039(98)02000-0
日期:1998.12
Cerium-mediated conjugate additions of (diethoxyphosphinoyl) difluoromethyllithium to cyclic vinyl sulfoxides proceeded smoothly; thermal sulfoxide elimination afforded the products of formal vinylation, attaching the difluoromethylenephosphonato group to an alkenyl carbon atom. With acyclic vinyl sulfoxides, the addition occurred in moderate to poor yield. Addition failed completely in the absence
The reaction of both isomers of methyl styryl sulfoxide (Ia) with the title chloride affords methyl phenacyl sulfide (IIa) and phenyl(α-methylthio)acetaldehyde (IIIa) besides β-chlorostyryl methyl sulfide (IVa). Phenyl styryl sulfoxide reacts similarly.
Herein, we report a convenient synthesis of aryl-substituted (E)-vinylic NH-sulfoximines via the Horner–Wadsworth–Emmons reaction without the use of protection–deprotection group strategies.