158807-51-3Relevant articles and documents
Studies on N-activation for the lipase-catalyzed enantioselective preparation of β-amino esters from 4-phenylazetidin-2-one
Sundell, Riku,Kanerva, Liisa T.
, p. 1500 - 1506 (2015/03/04)
The effect of N-substitution was examined for the enantio-selective lipase-catalyzed ring-opening reaction of racemic 4-phenylazetidin-2-one with methanol in dry organic solvents. Marked differences in the reactivity of various N-protected 4-phenylazetidin-2-ones were observed. Preparativescale reactions with Candida antarctica lipase B (Novozym 435 preparation) yielded N-acylated methyl (R)-3-amino-3- phenylpropanoates with enantiomeric excess (ee) values >99% in up to a 49% isolated yield, whereas Thermomyces lanuginosus lipase (Lipozyme TM IM) gave enantiomerically enriched methyl (S)-3-acetamido-3-phenylpropanoate. Candida antarctica lipase A catalyzed the cleavage of the N-chloroacetyl protective group, whereas all of the other examined lipases underwent the ring-opening reaction.
Disulfonimide-catalyzed asymmetric synthesis of β3-amino esters directly from N-Boc-amino sulfones
Wang, Qinggang,Leutzsch, Markus,Van Gemmeren, Manuel,List, Benjamin
, p. 15334 - 15337 (2013/11/06)
An asymmetric Mannich reaction of silyl ketene acetals with N-Boc-amino sulfones has been developed. A chiral disulfonimide efficiently catalyzes both the in situ generation of the corresponding N-Boc imines and the asymmetric Mannich reaction with excellent yields and enantioselectivities. Kinetic studies confirm a proposed stepwise mechanism.
Fluorinated β2- and β3-amino acids: Synthesis and inhibition of α-chymotrypsin
Peddie, Victoria,Pietsch, Markus,Bromfield, Karen M.,Pike, Robert N.,Duggan, Peter J.,Abell, Andrew D.
experimental part, p. 1845 - 1859 (2010/10/18)
The synthesis of a series of -fluorinated β2- and β3-amino acid derivatives is described. Stereoselective fluorination at the -carbon of the β3-amino acids was achieved by deprotonation with lithium diisopropylamide followed by treatment with N-fluorobenzenesulfonimide. Fluorination of β2-amino acids employed the chiral auxiliary (4R)-4-benzyl-2-oxazolidinone. The α-fluorinated amino acids and their non-fluorinated precursors were found to competitively inhibit α-chymotrypsin. Georg Thieme Verlag Stuttgart New York.
