Synthesis of 3,3-difluoro-2-azetidinones and 2,3-dideoxy-2,2-difluoro-3-amino-sugars through the reformatsky reaction of difluoroacetate with imine

One-pot synthesis of 4,4-difluoro-3-oxo-2-(triphenylphosphoranylidene)-δ-lactones by Reformatsky reaction

“…It was reported that the Reformatsky reactions of halodifluoroacetate with aldimines and chiral 1,3-oxazolidines usually gave difluorinated b-lactams [18][19][20][21]. However, the similar reactions of 4-bromo-4,4-difluoroacetoacetate with aldimines and ketimines were reported to give complicated results [22].…”

Reactivity Enhancement for Chiral Dirhodium(II) Tetrakis(Carboxamidates)

“…Thus oxidative cleavage of the acetone ketal of d-mannitol, [7] followed by imine formation, afforded 3 which was then treated with zinc dust and ethyl bromodifluoroacetate [8] to produce 4 as a mixture of diastereoisomers whose ratio was dependent on R 1 (Bn, syn/anti = 4.7; p-MeOC 6 H 4 CH 2 , syn/anti = 4.0; Ph 2 CH, syn/anti = 2.0). Chromatographic separation of the syn-isomer, alcoholysis, oxidation, [9] and esterification produced the azetidin-2-one product 5 that was deprotected [10] to afford the desired ligand.…”

An efficient synthetic method for Z-fluoroalkene dipeptide isosteres: Application to the synthesis of the dipeptide isostere of Sta-Ala

“…As the substrates, we chose g,g-difluoro-a,b-enoate derivatives having a hydroxyl group (Y = OH, 1a, 1b) or an amino group (Y = NHAnis, 1c) at the d-position as well as the corresponding hydrogen derivative (Y = H, 1d) to examine the reactivity of each substrate in organocopper mediated reactions [17,[23][24][25].…”