Highly Efficient Nickel-Based Heterogeneous Catalytic System with Nanosized Structural Organization for Selective Se−H Bond Addition to Terminal and Internal Alkynes

A simple heterogeneous Ni-based catalytic methodology was developed for regioselective hydroselenation of terminal alkynes and stereoselective hydroselenation of internal alkynes. The developed heterogeneous catalytic system is superior to the known homogeneous and heterogeneous catalysts for the Se−H bond addition to the triple bond of alkynes. The catalytic transformation was performed under mild conditions, thus avoiding byproducts formation. The mechanistic study revealed that the yield of the addition products depends on the catalyst particle size and rapidly increases upon decreasing particle size into the nanosized region. The present study describes a simple and efficient procedure for the formation of a self-organized nanosized catalytic system starting from an easily available precursor, Ni(acac) 2, without any special treatment.