528607-93-4Relevant academic research and scientific papers
Application of (S)- and (R)-methyl pyroglutamates as inexpensive, yet highly efficient chiral auxiliaries in the asymmetric Michael addition reactions
Cai, Chaozhong,Yamada, Takeshi,Tiwari, Rohit,Hruby, Victor J.,Soloshonok, Vadim A.
, p. 6855 - 6858 (2007/10/03)
Methyl N-(E-enoyl)pyroglutamates, derived from inexpensive and readily available in both enantiomeric forms pyroglutamic acid were found to be an efficient Michael acceptors in the addition reactions with nucleophilic glycine equivalent allowing for an ef
A practical asymmetric synthesis of enantiomerically pure 3-substituted pyroglutamic acids and related compounds
Soloshonok, Vadim A.,Cai, Chaozhong,Hruby, Victor J.
, p. 2172 - 2175 (2007/10/03)
DBU-catalyzed Michael addition reactions were shown to occur at room temperature between a nickel(II) complex of the Schiff base of glycine 1 and (S)- or (R)-N-(E-enoyl)-4-phenyl-3-oxazolidin-2-ones (2, see scheme). This reaction, which has an almost comp
Asymmetric Michael addition reactions of chiral Ni(II)-complex of glycine with (N-trans-enoyl)oxazolidines: Improved reactivity and stereochemical outcome
Soloshonok, Vadim A.,Cai, Chaozhong,Hruby, Victor J.
, p. 4265 - 4269 (2007/10/03)
Application of the (N-trans-enoyl)oxazolidines as Michael acceptors in the kinetically controlled additions with a Ni(II)-complex of the chiral Schiff base of glycine with (S)-o-[N-(N-benzylprolyl)amino]benzophenone 1 was shown to be synthetically advantageous over the alkyl enoylates, allowing for remarkable improvement in reactivity and, in most cases, diastereoselectivity of the reactions. While the stereochemical outcome of the Michael additions of the aliphatic (N-trans-enoyl)oxazolidines with complex 1 depended on the steric bulk of the alkyl group on the starting oxazolidines, the diastereoselectivity of the aromatic (N-trans-enoyl)oxazolidines reactions was found to be controlled by the electronic properties of the aryl ring. In particular, the additions of complex 1 with (N-cinnamoyl)oxazolidines, bearing electron-withdrawing substituents on the phenyl ring, afforded the (2S,3R)-configured products with synthetically useful selectivity and in quantitative chemical yield, thus allowing an efficient access to sterically constrained β-substituted pyroglutamic acids and related compounds. (C) 1999 Elsevier Science Ltd.
