Diethylzinc (Et2Zn) can be used as an efficient and chemoselective catalyst for the reduction of tertiary amides under mild reaction conditions employing cost-effective polymeric silane (PMHS) as the hydride source. Crucial for the catalytic activity was the addition of a substoichiometric amount of lithium chloride to the reaction mixture. A series of amides containing different additional functional groups were reduced to their corresponding amines, and the products were isolated in good-to-excellent yields.
A tandem α‐alkylation/asymmetric transfer hydrogenation of acetophenones with primary alcohols, mediated by a single ruthenium catalyst, is described. Under optimized reaction conditions and with use of [Ru(p‐cymene)Cl2]2 in combination with an amino acid hydroxyamide ligand, the chiral secondary alcohol products were isolated in moderate yields and in moderate to good enantiomeric excess (up to 89 % ee).
A novel electron deficient 4,6-bis(trifluoromethyl)-1,3-phenylene diphosphinite ligand 4 was developed and synthesized. Reaction of Ir precursors with ligand 4 gave chloro(hydride) pincer complex 5, which demonstrated a higher TON in alkane dehydrogenation reactions compared to similar phosphinite based pre-catalysts. The formation of cyclooctene (COE) and tert-butylethylene adducts of the 14e catalysts was also studied and the COE adduct is implicated as the resting state of the catalyst. All compounds were characterized by NMR spectroscopy and, in addition, the molecular structures of key complexes were confirmed by X-ray analysis.
A mild and highly efficient catalytic hydrosilylation protocol for room-temperature ester reductions has been developed using diethylzinc as the catalyst. The methodology is operationally simple, displays high functional group tolerance and provides for a facile access to a broad range of different alcohols in excellent yields.
The low-coordinate phosphorus compounds (Me(3)Si)(2)N-P=NSiMe(3), (Me(3)Si)(2)N-P(=S)=N(t)Bu and (Me(3)Si)(2)N-P(=NSiMe(3))(2) react with ((i)PrO)(3)M≡M(O(i)Pr)(3) (M = Mo, W) to form four- and five-membered metallacycles with intact endocyclic or exocyclic M≡M triple bonds. The first four-membered planar metallacycles, containing an M≡M triple bond were obtained in reaction with (Me(3)Si)(2)N-P=NSiMe(3).
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