02238nas a2200193   4500008004100000022001400041245013300055210006900188260000800257300001400265490000700279520150900286100002201795700002001817700002901837700002601866700002001892856013201912       2025                        eng d  a2044-475300asyn-Selective hydrosilylation and hydroboration of alkynes at room temperature catalyzed by a phosphine-free (NNN)Fe(ii) complex0 asynSelective hydrosilylation and hydroboration of alkynes at roo  cNOV  a6716-67250 v153 a<p>
	Catalytic hydrofunctionalization of alkynes is the ideal and atom-economical route to synthesize vinylsilanes and vinylboronates, which are valuable organic building blocks. However, the process suffers from using expensive phosphine-ligated catalysts, sensitive organometallic activators, and elevated reaction temperatures. To overcome these challenges, herein, we developed a series of phosphine-free (NNN)-ligated iron complexes and demonstrated their potential as efficient catalysts for the hydrosilylation and hydroboration of both internal and terminal alkynes using NaOtBu as an activator. The reactions proceeded smoothly using 1.5 mol% catalyst loading at room temperature and provided syn-selective vinylsilanes and vinylboronates. This hydrofunctionalization exclusively delivered mono-silylated and mono-borylated vinyls with tolerance of sensitive functionalities. At the same time, terminal alkynes provided excellent anti-Markovnikov selectivity with thermodynamically feasible beta-(E)-vinylsilanes and beta-(E)-vinylboronates. The presence of an N-H moiety in the ligand backbone is crucial in generating an Fe(ii) active catalyst and facilitating the catalytic process. Mechanistic investigations, including controlled reactions and external additive experiments, were performed to propose a redox-neutral reaction mechanism with iron maintaining its +2 oxidation state throughout the cycle. The DFT energy calculations unanimously support the proposed reaction mechanism.</p>
1 aPradhan, Chandini1 aDubey, Shivansh1 aSamal, Pragnya, Paramita1 aKrishnamurty, Sailaja1 aPunji, Benudhar  uhttps://library.ncl.res.in/content/syn-selective-hydrosilylation-and-hydroboration-alkynes-room-temperature-catalyzed-phosphine