Asymmetric Synthesis of cis-5-tert-Butylproline with Metal Carbenoid NH Insertion
摘要:
The highly stereoselective intramolecular metal carbenoid insertion reaction of sulfinimine-derived delta-amino delta-diazoesters is used to prepare cis-5-tert-butylproline. A concerted or nearly concerted metal carbenoid N-H insertion reaction mechanism is proposed.
Asymmetric Synthesis of β-Amino Carbonyl Compounds with <i>N</i>-Sulfinyl β-Amino Weinreb Amides
作者:Franklin A. Davis、M. Brad Nolt、Yongzhong Wu、Kavirayani R. Prasad、Danyang Li、Bin Yang、Kerisha Bowen、Seung H. Lee、John H. Eardley
DOI:10.1021/jo0402780
日期:2005.3.1
readily add to enantiopure N-sulfinyl β-aminoWeinrebamides providing the corresponding, stable, N-sulfinyl β-amino carbonyl compounds in good to excellent yields. This new methodology represents a general solution to the problem of β-amino carbonyl syntheses, which are important chiral building blocks and constituents of natural products. N-Sulfinyl β-aminoWeinrebamides are prepared by reaction of the
Asymmetric Aza-Henry Reactions from <i>N</i>-<i>p</i>-Tolylsulfinylimines
作者:José Luis García Ruano、Markus Topp、Jesús López-Cantarero、José Alemán、Modesto J. Remuiñán、M. Belén Cid
DOI:10.1021/ol051580d
日期:2005.9.1
[reaction: see text] N-Sulfinylimines derived from aromatic or aliphatic aldehydes and ketones react with nitromethane and NaOH in a highly diastereoselective manner under mild conditions. In the presence of TBAF, the reaction rates are strongly increased and the stereoselectivity is inverted. This method provides enantiomerically pure beta-nitroamines derived from enolizable aldimines and ketimines
Asymmetric synthesis of α-amino aldehydes from sulfinimine (N-sulfinyl imine)-derived α-amino 1,3-dithianes. Formal synthesis of (−)-2,3-trans-3,4-cis-dihydroxyproline
作者:Franklin A. Davis、Tokala Ramachandar、Jing Chai、Eduardas Skucas
DOI:10.1016/j.tetlet.2006.02.092
日期:2006.4
sulfinimine-derived N-sulfinyl α-amino 1,3-dithianes with aqueous 1,3-dibromo-5,5-dimethylhydantoin affords the corresponding N-tosyl α-amino aldehydes in good yield and high enantiomeric purity. These aldehydes can be reduced to amino alcohols and undergo the Wittig reaction to give allylic amines without epimerization. The utility of this methodology is illustrated in a formal synthesis of (−)-2,3-trans-3,4-cis-dihydroxyproline
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.