Asymmetric Synthesis of N-Substituted α-Aminobenzlactam via Crystallization-Induced Asymmetric Transformation of Covalent Diastereomer

Atropisomers and near-atropisomers: achieving stereoselectivity by exploiting the conformational preferences of aromatic amides

“…Thermodynamic stereocontrol has classically been used widely in ring synthesis -for example, equilibration to allow an all-equatorially substituted cyclohexane or an exo-substituted bicycle -and is operative in crystallisationinduced stereoselective transformations. [39][40][41][42][43][44][45][46][47] It has been shown to be an important strategy for achieving enantioselectivity with organolithium compounds. 48 Some applications to biaryl synthesis are discussed below, but the use of thermodynamic stereocontrol outside of these areas is rare.…”

Conversion of the Laboratory Synthetic Route of the N-Aryl-2-benzothiazolamine R116010 to a Manufacturing Method

“…By screening 22 chiral acids in numerous solvents, we found that it was possible to resolve the aminoketone 13 with ditoluoyltartaric acid in methanol. Moreover, after fine-tuning of the reaction conditions, the desired diastereomeric salt could be obtained in 90% yield (diastereomeric ratio 90/10) via a crystallization-induced diastereomeric resolution. − To our knowledge a crystallisation-based resolution of an α-tertiary amino ketone has not been reported before. The two enantiomers of the aminoketone 13 can equilibrate through the enol form.…”

Novel 2-[(benzylamino)methyl]pyrrolidine-3,4-diol derivatives as α-mannosidase inhibitors and with antitumor activities against hematological and solid malignancies

“…After protection of both amino and carboxylic groups, the intermediate 21 (Scheme 3) reacted with triflic anhydride to generate the corresponding triflate 22 (Scheme 3) in good yield. Suzuki cross-coupling 38,39 with phenylboronic acid, 4-(trifluoromethyl)phenylboronic acid and thienylboronic acid in toluene using tetrakis(triphenylphosphine)palladium as catalyst led to the desired N-tert-butyloxycarbonyl biphenylglycine methyl ester 23, N-tert-butyloxycarbonyl-4-(trifluoromethyl)biphenylglycine methylester 24 and N-tert-butyloxycarbonyl-4-(thienyl)phenylglycine methyl ester 25 (Scheme 3) in 84%, 70% and 84% yield, respectively. tert-Butylcarbamate was cleaved and the resulting amines 2-4 were submitted to reductive aminations with the pyrrolidinecarbaldehyde 1.…”