Synthesis of Enantiopure Sulfinimines (Thiooxime S-Oxides) Catalyzed by Yb(OTf)3 from p-Toluenesulfinamide and Aldehydes in Mild Reaction Conditions
摘要:
Enantiomerically pure sulfinimines as important building blocks in the asymmetric synthesis of amine derivatives are prepared in good to excellent yields from chiral p-toluenesulfinamide with aromatic, heteroaromatic, and aliphatic aldehydes. The unprecedented feature of the reported procedure is that the formation of the sulfinimines was achieved by the catalytic action of Yb(OTf)(3) in THF at room temperature. The reaction conditions were also applicable to Ellman's sulfinimines.
Diastereoselective Trifluoromethylation of Chiral<i>N</i>-(Tolylsulfinyl)imines in the Presence of Lewis Bases
作者:Yoshikazu Kawano、Teruaki Mukaiyama
DOI:10.1246/cl.2005.894
日期:2005.7
A diastereoselctive trifluoromethylation of chiral N-(tolylsulfinyl)imines with (trifluoromethyl)trimethylsilane in the presence of Lewis bases such as tetrabutylammonium acetate or phenoxide proceeded smoothly to afford the corresponding trifluoromethylated adducts in good yields.
Convenient Asymmetric Synthesis of β-Substituted α,α-Difluoro-β-amino Acids via Reformatsky Reaction between Davis' <i>N</i>-Sulfinylimines and Ethyl Bromodifluoroacetate
作者:Alexander Sorochinsky、Natalia Voloshin、Andrey Markovsky、Michael Belik、Nobuhiro Yasuda、Hidehiro Uekusa、Taizo Ono、Dmitrii O. Berbasov、Vadim A. Soloshonok
DOI:10.1021/jo030082k
日期:2003.9.1
N-sulfinylimines were found to be efficient as chiral imine equivalents in the high-temperature Reformatsky-type additions with BrZnCF(2)COOEt affording an efficient approach to the enantiomerically pure alpha,alpha-difluoro-beta-amino acids. High chemical and stereochemical yields (drs > 9:1, and as high as 99:1) render this method immediately useful for preparing the target amino acids.
Asymmetricradicaladdition of ethers to enantiopure aromatic N-p-toluenesulfinyl aldimines has been achieved. The requisite radicals were generated by dimethylzinc-air. Lewis acid activation of the N-p-toluenesulfinyl aldimines followed by radicaladdition gives a mixture of sulfinamide and sulfonamide products. Subsequent treatment of the mixture with dry m-CPBA affords the sulfonamide product in
Asymmetric Thio-Michael/Nucleophilic Addition Domino Reaction with Chiral <i>N</i>-Sulfinimines
作者:Akio Kamimura、Hidenori Okawa、Yuki Morisaki、Shingo Ishikawa、Hidemitsu Uno
DOI:10.1021/jo062251h
日期:2007.4.1
active N-sulfinimines underwent stereoselective Michael/nucleophilicaddition domino reaction triggered by magnesium thiolate to give α-phenylthiomethyl-β-(N-sulfinylamino) esters in high diastereomeric excess. The adducts were readily converted into optically active α-methylene-β-(N-sulfinylamino)esters so that this reaction provides a useful asymmetric aza-Baylis−Hillman-equivalent method.
Lewis base-catalyzed diastreoselective Mannich-type reaction between ketene silyl acetals and chiral sulfinimines proceeded smoothly to afford the corresponding β-amino carbonyl compounds in good to high yields with high selectivities.