Efficient synthesis of optically active α-quaternary amino acids by highly diastereoselective [2,3]-rearrangement of allylic ammonium ylides.
نویسندگان
چکیده
A pincer-like chiral auxiliary strategy for synthesizing various optically active α,α-disubstituted amino acids in high yields with excellent enantioselectivities is described.
منابع مشابه
An isothiourea-catalyzed asymmetric [2,3]-rearrangement of allylic ammonium ylides.
Benzotetramisole promotes the catalytic asymmetric [2,3]-rearrangement of allylic quaternary ammonium salts (either isolated or prepared in situ from p-nitrophenyl bromoacetate and the corresponding allylic amine), generating syn-α-amino acid derivatives with excellent diastereo- and enantioselectivity (up to >95:5 dr; up to >99% ee).
متن کاملAsymmetric Sommelet-Hauser rearrangement of N-benzylic ammonium salts.
The Stevens and Sommelet–Hauser rearrangement of ammonium ylides are known as useful transformations for organic synthesis because they convert a readily accessible C–N bond into a new C–C bond. The Stevens rearrangement has been widely used for the asymmetric synthesis of α-amino acid derivatives, whereas the Sommelet–Hauser rearrangement is much less common because the Sommelet–Hauser rearran...
متن کاملAmmonium ylides for the diastereoselective synthesis of glycidic amides.
A highly trans-selective protocol for the synthesis of glycidic amides was developed. This approach gave access to oxiranes by reacting stabilised ammonium ylides bearing an α-carbonyl group and aromatic aldehydes in moderate to good yields.
متن کاملChiral Induction in Cycloaddition Reactions of Azomethine Ylides to Synthesis of New Enantiomerically Pure Spiro Oxindolopyrrolizidines
An efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. The process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating...
متن کاملChiral Induction in Cycloaddition Reactions of Azomethine Ylides to Synthesis of New Enantiomerically Pure Spiro Oxindolopyrrolizidines
An efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. The process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Chemical communications
دوره 48 58 شماره
صفحات -
تاریخ انتشار 2012