The first catalytic asymmetric method to prepare enantioenriched N,S-acetals using chiral BINOL phosphoric acids is reported. The reaction combines N-acyl imines with thiols to generate products in excellent yield and enantioselectivity. The addition reaction could also be achieved with an exceptional substrate to catalyst (S/C) molar ratio. Electron-rich and electron-deficient aromatic N-acyl imines, as well as a broad range of aliphatic and aromatic thiols, showed excellent reactivity.

A new method to synthesize chiral α-amino phosphine oxides is reported. The reaction combines N-substituted imines and diphenylphosphine oxide, and is catalyzed by a chiral magnesium phosphate salt. A wide variety of aliphatic and aromatic aldimines substituted by electron neutral benzhydryl or dibenzocycloheptene groups were excellent substrates for the addition reaction. The dibenzocycloheptene protected imines afforded improved enantioselectivity in the resulting products. Substituted diphenylphosphine oxide nucleophiles also showed good reactivity.

Zinc complexes of three new amide-appended ligands have been prepared and isolated. These complexes, [(dpppa)Zn](ClO4)2 (4(ClO4)2; dpppa = N-((N,N-diethylamino)ethyl)-N-((6-pivaloylamido-2-pyridyl)methyl)-N-((2-pyridyl)methyl)amine), [(bdppa)Zn](ClO4)2 (6(ClO4)2; bdppa = N,N-bis((N,N-diethylamino)ethyl)-N-((6-pivaloylamido-2-pyridyl)methyl)amine), and [(epppa)Zn](ClO4)2 (8(ClO4)2; epppa = N-((2-ethylthio)ethyl)-N-((6-pivaloylamido-2-pyridyl)methyl)-N-((2-pyridyl)methyl)amine), have been characterized by X-ray crystallography (4(ClO4)2 and 8(ClO4)2), 1H and 13C NMR, IR, and elemental analysis. Treatment of 4(ClO4)2 or 8(ClO4)2 with 1 equiv of Me4NOH.5H2O in methanol-acetonitrile (5:3) results in amide methanolysis, as determined by the recovery of primary amine-appended forms of the chelate ligand following removal of the zinc ion. These reactions proceed via the initial formation of a deprotonated amide intermediate ([(dpppa-)Zn]ClO4 (5) and [(epppa-)Zn]ClO4 (9)) which in each case has been isolated and characterized (1H and 13C NMR, IR, elemental analysis). Treatment of 6(ClO4)2 with Me4NOH.5H2O in methanol-acetonitrile results in the formation of a deprotonated amide complex, [(bdppa-)Zn]ClO4 (7), which was isolated and characterized. This complex does not undergo amide methanolysis after prolonged heating in a methanol-acetonitrile mixture. Kinetic studies and construction of Eyring plots for the amide methanolysis reactions of 4(ClO4)2 and 8(ClO4)2 yielded thermodynamic parameters that provide a rationale for the relative rates of the amide methanolysis reactions. Overall, we propose that the mechanistic pathway for these amide methanolysis reactions involves reaction of the deprotonated amide complex with methanol to produce a zinc methoxide species, the reactivity of which depends, at least in part, on the steric hindrance imparted by the supporting chelate ligand. Amide methanolysis involving a zinc complex supported by a N2S2 donor chelate ligand (3(ClO4)2) is more complicated, as in addition to the formation of a deprotonated amide intermediate free chelate ligand is present in the reaction mixture.

The first described reaction between N-tosylhydrazone and SO2 is reported to provide alkyl sulfonamides in the presence of various amines. In this procedurally simple method, hydrazones of both unsaturated aldehydes and ketones proceed in moderate to excellent yields. Primary and secondary aliphatic amines are accommodated in this reaction, which provides a novel route to sulfonamides.

Treatment of the mononuclear amide-appended zinc complex [(ppbpa)Zn](ClO4)2 (1(ClO4)2) with Me4NOH.5H2O in CD3CN/D2O (3:1) results in the formation of the deprotonated amide species [(ppbpa-)Zn]ClO4 (2). Upon heating in CD3CN/D2O, this complex undergoes amide hydrolysis to produce a zinc carboxylate product, [(ambpa)Zn(O2CC(CH3)3)]ClO4 (3). X-ray crystallography, 1H and 13C NMR, IR, and elemental analysis were used to characterize 3. The hydrolysis reaction of 1(ClO4)2 exhibits saturation kinetic behavior with respect to the concentration of D2O. Variable-temperature kinetic studies of the amide hydrolysis reaction yielded DeltaH++ = 18.0(5) kcal/mol and DeltaS++ = -22(2) eu. These activation parameters are compared to those of the corresponding amide methanolysis reaction of 1(ClO4)2.