Direct Zn–diamine promoted reduction of CO and CN bonds by polymethylhydrosiloxane in methanol
作者:Virginie Bette、André Mortreux、Christian W. Lehmann、Jean-François Carpentier
DOI:10.1039/b210144k
日期:2003.1.23
Ketones and imines are chemoselectively reduced at room temperature in methanol to the corresponding alcohols and amines in high yields in a one-step procedure using polymethylhydrosiloxane (PMHS) and a simple zincâdiamine catalyst.
Synthesis of Group 4 Metal Complexes Stabilized by an Amine-Bridged Bis(phenolato) Ligand and Their Catalytic Behavior in Intermolecular Hydroamination Reactions
bis(phenolato) ligand, have been synthesized and characterized. Although 1 and 2 were inactive in catalyzing intermolecularhydroamination reactions, cationic complexes generated in situ from treatment of 1 and 2 with borate [Ph3C][B(C6F5)4], respectively, were found to be highly active. In general, excellent yields (up to >99%) and 100% regioselectivity for a broad range of terminalalkynes and anilines
Pentacoordinate zirconium complexes 5 and 7 stabilized by amine-bridged bis(phenolato) ligands are more active than hexacoordinate complexes 1–4 in catalyzing intermolecular hydroamination reactions.
Development of highly enantioselective new Lewis basic N-formamide organocatalysts for hydrosilylation of imines with an unprecedented substrate profile
作者:Pengcheng Wu、Zhouyu Wang、Mounuo Cheng、Li Zhou、Jian Sun
DOI:10.1016/j.tet.2008.09.034
日期:2008.12
ketimines and non-methyl ketimines were catalyzed to afford the desired amines in good to high yield and enantioselectivity. In particular, catalyst 6e enabled the reduction of the difficult bulky ketimines to be highly efficient and enantioselective, affording up to 99% yield and 97% ee. This catalyst proved to prefer the relatively bulkier non-methyl acyclic ketimines to the methyl ketimines as substrate
The Zn-promoted direct reduction of various ketones, including alkyl aryl ketones, α- and β-keto esters, α- and β-keto amides, into the corresponding alcohols with polymethylhydrosiloxane (PMHS) in protic conditions is reported. The reaction proceeds chemoselectively under smooth conditions, with simple catalyst combinations based on a zinc precursor [ZnEt2, Zn(OMe)2, Zn(OH)2] and a 1,2-diamine ligand