Metalation regioslectivity of 3,5-dichlorobenzamides is a function of the type of amide (secondary versus tertiary) used in the sequence. Metalation at the 2-position (adjacent to the carboxamide functional group) occ...Metalation regioslectivity of 3,5-dichlorobenzamides is a function of the type of amide (secondary versus tertiary) used in the sequence. Metalation at the 2-position (adjacent to the carboxamide functional group) occurs when the secondary benzamide is metalated with sec-butyllithium/ TMEDA mediated through complex-induced proximity effects (CIPE) process, whereas metalation with sec-butyllithium/TMEDA occurs exclusively at the 4-position when the tertiary benzamide is used under identical reaction conditions.展开更多
The reaction of the 16e half-sandwich complex Cp*Co(S2C2B10H10) (1) (Cp* = pentamethylcyclopentadienyl) with excess methyl acetylene monocarboxylate, HC≡C-CO2Me, affords the 18e complexes 2-6. Compound 2 bears a B-CH...The reaction of the 16e half-sandwich complex Cp*Co(S2C2B10H10) (1) (Cp* = pentamethylcyclopentadienyl) with excess methyl acetylene monocarboxylate, HC≡C-CO2Me, affords the 18e complexes 2-6. Compound 2 bears a B-CH2 unit in which B-substitution occurs in the B(3)/B(6) position of the ortho-carborane cage. Complexes 3-6 are geometrical isomers, in which the alkyne is twofold inserted into one of the Co-S bonds in all the four possible ways. Treatment of 1 with excess 3-butyn-2-one or phenyl ethynyl ketone, HC≡C-C(O)R (R = Me, Ph), at ambient temperature leads to the 18e complexes 7-10, respectively, with two alkynes inserted into one of the Co-S bonds. All the new complexes were fully characterized by spectroscopic techniques and elemental analysis. The solid-state structures of 2, 3, 5, 7, 8, 9 and 10 were further characterized by X-ray structural analysis.展开更多
文摘Metalation regioslectivity of 3,5-dichlorobenzamides is a function of the type of amide (secondary versus tertiary) used in the sequence. Metalation at the 2-position (adjacent to the carboxamide functional group) occurs when the secondary benzamide is metalated with sec-butyllithium/ TMEDA mediated through complex-induced proximity effects (CIPE) process, whereas metalation with sec-butyllithium/TMEDA occurs exclusively at the 4-position when the tertiary benzamide is used under identical reaction conditions.
基金the National Natural Science Foundation of China (20925104,90713023,20771055,20721002)the Major State Basic Research Development Program of China (2006CB806104)the National Basic Research Program of China (2007CB925101,2010CB923303)
文摘The reaction of the 16e half-sandwich complex Cp*Co(S2C2B10H10) (1) (Cp* = pentamethylcyclopentadienyl) with excess methyl acetylene monocarboxylate, HC≡C-CO2Me, affords the 18e complexes 2-6. Compound 2 bears a B-CH2 unit in which B-substitution occurs in the B(3)/B(6) position of the ortho-carborane cage. Complexes 3-6 are geometrical isomers, in which the alkyne is twofold inserted into one of the Co-S bonds in all the four possible ways. Treatment of 1 with excess 3-butyn-2-one or phenyl ethynyl ketone, HC≡C-C(O)R (R = Me, Ph), at ambient temperature leads to the 18e complexes 7-10, respectively, with two alkynes inserted into one of the Co-S bonds. All the new complexes were fully characterized by spectroscopic techniques and elemental analysis. The solid-state structures of 2, 3, 5, 7, 8, 9 and 10 were further characterized by X-ray structural analysis.
