Ligand-controlled Cobalt-Catalyzed formation of Carbon–Boron bonds: Hydroboration vs C H/B–H dehydrocoupling

Cobalt pincer-type complexes demonstrating unique selectivity for the hydroboration reaction of olefins under mild conditions

“…59 In the case of the non-anionic form, its lower catalytic activity is probably compensated by the β-silicon effect, stabilizing the alkyl complex and remarkably accelerating the reaction rate. [60][61][62] Based on this and our previous studies on pincer cobalt complexes, as well as literature reports, [44][45][46]57,[63][64][65][66][67] we postulate that in the reaction mixture, as a result of activation with pinacolborane or sodium triethylboron hydride, the two Scheme 9 Experiments verifying the potential formation of borane as a hidden reaction catalyst.…”

“…This is in accordance with our previous reports in which we demonstrated the possibility of the hydroboration of silylacetylenes on the described catalyst. 46 To prove the synthetic potential of the developed method, we tested its scalability by performing two gram-scale reactions for both the solvent-free hydroboration of vinylsilanes and the reaction with an activator. In both cases, we observed quantitative conversion which resulted in excellent isolation yields (Scheme 7).…”

“…45 Moreover, we have demonstrated the possibility of controlling the direction of the reaction of silylacetylenes with pinacolborane toward hydroboration or dehydrogenative borylation products depending on the substituents at the triazine ring. 46 Now we present an efficient anti-Markovnikov selective protocol for the hydroboration of a broad range of alkenes (amines, carbonates, ethers, vinylarenes, vinylsilanes, natural products) under mild conditions using an inexpensive and Earth-abundant cobalt complex as a catalyst. Moreover, the presented procedure allows selective functionalization of alkenyl(vinyl) silanes and alkynyl(vinyl)silanes with the retention of the alkenyl or vinyl group, respectively, leading to interesting bifunctional precursors of modern materials, in which the free alkenyl group allows further modification of the obtained polymers or their crosslinking.…”

Access to germasiloxanes and alkynylgermanes mediated by earth-abundant species

“…Thus, we sought the method leading to versatile germanium compounds that blends the high selectivity of TM-mediated approaches with the practicality of a base-promoted protocol. Based on our recent success in activating silylacetylenes under sustainable catalysis [45][46][47][48][49] , we reasoned that an appropriate catalytic manifold could provide an efficient platform to generate diversified libraries of organogermanes. In this…”

Silicon–nitrogen bond formation via dealkynative coupling of amines with bis(trimethylsilyl)acetylene mediated by KHMDS

“…Sustainable and eco-friendly synthetic approaches proceeded by the main-group catalysis have gained recent significant attention. [39][40][41][42][43][44] On the basis of our recent success in activating silylacetylenes under sustainable catalysis, [45][46][47][48] we reasoned that an appropriate catalytic manifold could provide an efficient platform to generate diversified libraries of trimethylsilylated amines. In this communication, we report on the catalytic silylation of primary amines with bis(trimethylsilyl)acetylene (BTMSA) for the construction of N-Si bonds via dealkynative coupling, by using potassium bis(trimethylsilylamide) as the catalyst (Figure 1, f).…”