Enantioselective Synthesis of α-Fluoro-β3-amino Esters: Synthesis of Enantiopure, Orthogonally Protected α-Fluoro-β3-lysine
摘要:
The scope of a tandem conjugate addition fluorination sequence performed on alpha,beta-unsaturated esters using the enantiopure lithium amide derived from (S)-N-benzyl-N-(alpha-methylbenzyl)amine, and the electrophilic fluorinating agent N-fluorobenzenesulfonimide has been investigated. Using this method, a-fluoro-beta(3)-amino esters can be obtained in up to quantitative yield and 80:20 to >99:1 dr. This simple methodology does not rely on the use of alpha-amino acids from the chiral pool and thus provides the potential for the preparation of enantiopure alpha-fluoro-beta(3)-amino acids with a wide variety of side chains. Its utility was demonstrated through the synthesis of orthogonally protected (2S,3S)-alpha-fluoro-beta(3)-lysine.
Enantioselective Synthesis of α-Fluoro-β<sup>3</sup>-amino Esters: Synthesis of Enantiopure, Orthogonally Protected α-Fluoro-β<sup>3</sup>-lysine
作者:Peter J. Duggan、Martin Johnston、Taryn L. March
DOI:10.1021/jo101600c
日期:2010.11.5
The scope of a tandem conjugate addition fluorination sequence performed on alpha,beta-unsaturated esters using the enantiopure lithium amide derived from (S)-N-benzyl-N-(alpha-methylbenzyl)amine, and the electrophilic fluorinating agent N-fluorobenzenesulfonimide has been investigated. Using this method, a-fluoro-beta(3)-amino esters can be obtained in up to quantitative yield and 80:20 to >99:1 dr. This simple methodology does not rely on the use of alpha-amino acids from the chiral pool and thus provides the potential for the preparation of enantiopure alpha-fluoro-beta(3)-amino acids with a wide variety of side chains. Its utility was demonstrated through the synthesis of orthogonally protected (2S,3S)-alpha-fluoro-beta(3)-lysine.
The Synthesis of Enantiopure α-Fluoro and α,α-Difluoro-β3-Arginine Derivatives
作者:Taryn L. March、Jamie A. Freemont、Geoff Dumsday、Martin R. Johnston、Peter J. Duggan
DOI:10.1071/ch13590
日期:——
The synthesis of a set of monofluorinated, difluorinated, and non-fluorinated N-acetylated-β3-arginine esters, potential inhibitors of trypsin-like proteases, is described. Elaboration to the target compounds from previously reported enantiopure precursors derived from 3-hydroxypropanal involved 6–7 steps and was achieved in 48–65 % overall yield. The α,α-difluoro-β3-arginine derivative was found to