DMSO methylates a broad range of amines in the presence of formic acid, providing a novel, green and practical method for aminemethylation. The protocol also allows the one‐pot transformation of aromatic nitro compounds into dimethylated amines in the presence of a simple iron catalyst.
Synthesis of tertiary arylamines: Lewis acid-catalyzed direct reductive N-alkylation of secondary amines with ketones through an alternative pathway
作者:Onkar S. Nayal、Maheshwar S. Thakur、Vinod Bhatt、Manoranjan Kumar、Neeraj Kumar、Bikram Singh、Upendra Sharma
DOI:10.1039/c6cc04381j
日期:——
We report herein a highly efficient, tin(II)/PMHS catalyzed reductive N-alkylation of arylamines with ketones affording tertiary arylamines. Very wide substrate scope was observed for current catalytic method as all six...
Ligand-free Iron(II)-Catalyzed N-Alkylation of Hindered Secondary Arylamines with Non-activated Secondary and Primary Alcohols <i>via</i>
a Carbocationic Pathway
作者:Onkar S. Nayal、Maheshwar S. Thakur、Manoranjan Kumar、Neeraj Kumar、Sushil K. Maurya
DOI:10.1002/adsc.201701183
日期:2018.2.15
Secondary benzylic alcohols represent a challenging class of substrates for N‐alkylation of amines. Herein, we describe an iron(II)‐catalyzed eco‐friendly protocol for N‐alkylation of secondary arylamines with secondary benzyl alcohols through a carbocationic pathway instead of the known borrowinghydrogen transfer (BHT) approach. Transiently generated carbocations, produced from alcohols via self‐condensation
The use of the well‐defined [Ru(triphos)(tmm)] catalyst, CO2 as C1 source, and H2 as reducing agent enabled the reductive methylation of isolated imines, as well as the direct coupling of amines with aldehydes and the subsequent reductive methylation of the in situ formed imines. The method, which afforded the corresponding N‐methyl amines in very good to excellent yields, was also used for the preparation
Iridium-Catalyzed Asymmetric Hydrogenation of Unfunctionalized Enamines
作者:Alejandro Baeza、Andreas Pfaltz
DOI:10.1002/chem.200802576
日期:2009.2.23
Optically active tertiary amines are readily prepared by iridium‐catalyzed asymmetrichydrogenation of unfunctionalizedenamines (see scheme). The best enantioselectivities with >90 % ee were obtained with N‐aryl‐ and N‐benzyl‐substituted enamines with a terminal double bond. The hydrogenation of enamines derived from cyclic ketones, which has not been reported yet with other catalysts, gave enantiomeric