Efficient and Selective Synthesis of E‐Vinylamines via Tungsten(0)‐Catalyzed Hydroamination of Terminal Alkynes

The hydroamination of terminal alkynes (RC CH = phenylacetylene, 4-methylphenylacetylene, 4-fluorophenylacetylene, 1-hexyne, methyl 2-propynyl ether, prop-2-yn-1-ol) with secondary amines (piperidine, pyrrolidine, morpholine, piperazine, methylpiperazine, 4-methylpiperidine and 3-methylpiperidine) was achieved in high yield (up to 99%), regioselectivity (only anti-Markovnikov product) and stereoselectivity (only E-isomers) within a maximum of 5 h in reactions catalyzed by the tungsten tetracarbonyl complex cis-[W(CO)(4)(piperidine)(2)] at 90 degrees C without any additional solvent.