Hydroamination of Terminal Alkynes by Amines Catalyzed by Copper Heteropoly Salts: A Simple Approach Towards Imine Synthesis

Abstract

Abstract:The hydroamination reaction offers a very attractive route for the synthesis of alkylated amines and their derivatives with no byproduct formation. Heterogeneous intermolecular hydroamination reactions of alkynes with aromatic amines using different inexpensive copper salts of hetropolyacid catalysts were investigated. Among heteropoly salts, copper salts of silicotungstic acid showed highest activity. Reactivity of aromatic amines increased with increase in its basicity. Acidity in heterogeneous catalyst can act as promoter in hydroamination of alkynes.

[2.2]Paracyclophanediyldiphosphane Complexes of Gold

“…Intermolecular Hydroamination: The substrates were purchased from Aldrich, AlfaAesar and Acros. The 1 H NMR spectra of N ‐(methylbenzylidene)aniline,40 N ‐(1‐phenylethylidene)‐2,4,6‐trimethylaniline,41 and N ‐[1‐(cyclohex‐1‐en‐1‐yl)ethylidene]‐2,4,6‐trimethylaniline are in agreement with the previously reported data 42…”

Synthesis, reactivity and applications of zinc–zinc bonded complexes

“…63 Hydroamination describes the addition of an N-H bond of an amine to an alkene or alkyne in one step with subsequent formation of nitrogen containing compounds. 72 In the catalytic studies the activity of dizincocene 1 was compared with previously published catalysts [73][74][75][76][77][78][79] by using the standard reaction, the addition of 2,4,6-trimethylaniline to phenylethyne (Scheme 19). These studies clearly showed the high potential of 1 for this type of reaction.…”

Comparison of Decamethyldizincocene [(η5-Cp*)2Zn2] versus Decamethylzincocene [Cp*2Zn] and Diethylzinc Et2Zn As Precatalysts for the Intermolecular Hydroamination Reaction

“…As test reaction we used the addition of 2,4,6-trimethylaniline to phenylethyne because this reaction has also been studied with many other reported catalysts (Table ). ,− Most reported catalysts for this reaction shown in Table are based on group 11 metals, although there are some exceptions such as a titanium catalyst (Table , entry 5). All three zinc catalysts ( 1 – 3 ) (Table , entries 1–3) catalyze the transformation at room temperature, whereas most of the other systems operate in the range 90–110 °C (Table , entries 4–9 and 11–13).…”

“…The 1 H NMR spectra of N -(methylbenzylidene)aniline, methylphenyl(1-phenylvinyl)amine, N -(1-phenylethylidene)-4-chloroaniline, N -(1-phenylethylidene)-2,4,6-trimethylaniline, N -[1-(4-bromophenyl)ethylidene)]benzamine, N,N -dimethyl-4-[1-(phenylimino)]ethylaniline, N -[1-(1-cyclohexene-1-yl)ethylidene]benzamine, N -(1-methylheptylidene)benzamine, 4-chlor- N -(1-methylheptylidene)benzamine, and N -(1-phenylethylidene)benzmethanamine conform to the literature.…”