117681-86-4Relevant articles and documents
Dearomative [2,3] sigmatropic rearrangement of ammonium ylides followed by 1,4-elimination to form α-(ortho-vinylphenyl)amino acid esters
Tayama, Eiji,Sotome, Sho
, p. 4833 - 4839 (2018)
A base-induced dearomative [2,3] sigmatropic rearrangement of amino acid ester-derived ammonium salts followed by 1,4-elimination produced α-(ortho-vinylphenyl)amino acid esters. The reaction of azetidine-2-carboxylic acid-derived ammonium salt, (1S,2S,1′R)-3b, proceeded with a perfect N-to-C chirality transfer to afford α-(ortho-vinylphenyl)azetidine-2-carboxylic acid ester, (R)-5 (99% ee). On the other hand, the reaction of glycine-derived ammonium salt (R)-6a, which involves an efficient chirality transfer from a chiral benzylic carbon to an α-carbon of an ester carbonyl giving the optically active α-(ortho-vinylphenyl)glycine ester, (R)-8a (85% ee), was demonstrated. Although this dearomative [2,3] rearrangement followed by 1,4-elimination has limitations with regard to the structures of the substrates, our method provides unique access to substituted α-arylamino acid derivatives.
Asymmetric Sommelet-Hauser rearrangement of N-benzylic ammonium salts
Tayama, Eiji,Kimura, Hiroshi
, p. 8869 - 8871 (2008/09/19)
(Chemical Equation Presented) [2,3] over [1,2]: The asymmetric Sommelet-Hauser rearrangement of an ammonium salt derived from N-benzylic proline-derived or N-benzylic glycine (-)-8-phenylmenthol ester is shown to proceed with remarkably high levels of stereoselectivity. The method provides unique and efficient access to optically active α-aryl amino acid derivatives.
Asymmetric induction in acyclic radical reactions: Enantioselective syntheses of (S)-2-deuterioglycine and (R)-2-deuterioglycine
Hamon,Massay-Westropp,Razzino
, p. 6419 - 6428 (2007/10/02)
The (-)-8-phenylmenthol esters of N-Boc-glycine and N-Boc-2,2-dideuterioglycine were brominated with N-bromosuccinimide and the bromo compounds were reduced with tri-n-butyldeuteriostannane and tri-n-butylstannane respectively, to give the chiral glycine derivatives in 90% optical yield. Hydrolysis yielded the amino acid without racemisation.