Use of a Cyclometalated Iridium(III) Complex Containing a N<sup>∧</sup>C<sup>∧</sup>N-Coordinating Terdentate Ligand as a Catalyst for the α-Alkylation of Ketones and <i>N</i>-Alkylation of Amines with Alcohols
作者:Pengcheng Liu、Ran Liang、Lei Lu、Zhentao Yu、Feng Li
DOI:10.1021/acs.joc.6b02758
日期:2017.2.17
A cyclometalated iridium(III) complexcontaining a N∧C∧N-coordinating terdentate ligand [Ir(dpyx-N,C,N)Cl(μ-Cl)]2 was found to be a general and highly effective catalyst for the α-alkylation of ketones and N-alkylation of amines with alcohols. In the presence of catalyst (1 mol % Ir) and base (0.2–0.5 equiv), a variety of desirable products were obtained in good yields under an air atmosphere. Notably
catalytic system was developed in N-alkylation reaction of primary amines with alcohols through a hydrogenautotransfer process. This Au(I) catalytic system shows excellent selectivity for mono-alkylation of primary amines with benzyl alcohol under moderate temperature of 100 °C (only secondary amines as product). The possible mechanism of this hydrogenautotransfer reaction with the catalytic system
Cross-dehydrogenative coupling strategy for phosphonation and cyanation of secondary N-alkyl anilines by employing 2,3-dichloro-5,6-dicyanobenzoquinone
has been developed firstly under mild reaction conditions. Based on detailed optimization of reaction conditions, the substrate generality of N-alkyl anilines and various hydrogen phosphonates has been investigated, and a series of versatile α-aminophosphonates and α-aminonitriles were therefore furnished in good to excellent yields. A plausible collective reaction mechanism through dehydrogenation to
manganese-catalyzed N-alkylation reaction of amines with alcohols via hydrogen autotransfer strategy has been demonstrated. The developed practical catalytic system including an inexpensive, nontoxic, commercially available MnCl2 or MnBr(CO)5 as the metal salt and triphenylphosphine as a ligand provides access to diverse aromatic, heteroaromatic, and aliphatic secondary amines in moderate-to-high yields