The methyl–amide complex [TaCp*(NBu)Me(NMe2)] (1a) was isolated by reaction of the chloro–methyl [TaCp*(NBu)MeCl] complex with LiNMe2. Reaction of the mono-amide compounds [TaCp*(N Bu)XY] (X=NMe2, Y=Me (1a); X=NHBu, Y=Me (1b), Cl (1c)) with CO2 gives the h-carbamate derivatives [TaCp*(NBu)(h-O2CX)Y] (X=NMe2, Y=Me (2a); X=NHBu, Y=Me (2b), Cl (2c)). A similar reaction with the di-amide complex [T...

The title compound, C(25)H(44)N(4)O(5), exhibits a turn with the main chain reversing direction, held together by an intramolecular N-H.O hydrogen bond. In the urea fragment, a notable amide C-N bond between the carboxyl C and the tertiary N atom shows marked single-bond character [1.437 (2) A]. The dihedral angle of the beta-alanyl residue, centrally located in the turn, is gauche [69.2 (2) de...

New ruthenium Grubbs' and Hoveyda-Grubbs' second generation catalysts bearing N-alkyl/N-isopropylphenyl N-heterocyclic carbene (NHC) ligands with syn or anti backbone configuration were obtained and compared in model olefin metathesis reactions. Different catalytic efficiencies were observed depending on the size of the N-alkyl group (methyl or cyclohexyl) and on the backbone configuration. The...

The infrared spectra of CH3Cl + H2O isolated in solid neon at low temperatures have been investigated. The CH3Cl + H2O system is remarkable because of its propensity to form CH3Cl:H2O and CH3Cl:(H2O)n (n > or = 2) complexes. We focus here on the CH3Cl:H2O species. Low concentration studies (0.01-0.5%) and subsequent annealing lead to formation of the 1:1 CH3Cl:H2O complex with O-H. . .Cl-C or O...