Dehydrogenative Silylation of Terminal Alkynes

Dehydrogenative silylation of terminal alkynes represents a pivotal strategy in organosilicon chemistry, enabling the direct installation of silyl groups onto acetylenic substrates through the formal dehydrogenation of silanes. This methodology circumvents the need for pre-activated reagents and offers atom-efficient routes to alkynylsilanes, which serve as versatile intermediates in cross-coupling, cycloaddition and further functionalisation. The process typically relies on transition-metal catalysis—ranging from precious metals such as platinum and iridium to earth-abundant first-row metals—although recent advances have also showcased metal-free and cooperative catalytic systems. Key challenges include controlling regio- and chemoselectivity in the presence of multiple reactive sites, suppressing hydrogenation side reactions, and broadening substrate scope to tolerate sensitive functional groups. The advancement of ligand design, catalyst activation strategies and mechanistic understanding has led to significant improvements in reaction efficiency, environmental sustainability and practical applicability across pharmaceuticals, materials science and agrochemicals.

Research from Nature Portfolio

Recent studies have introduced a dual catalytic system that synergises a nickel complex with an organophotoredox catalyst to activate both silane and alkyne substrates under visible light. This approach affords high yields of alkynylsilanes at ambient temperature, with remarkable tolerance towards halogenated and heteroaromatic substituents. Mechanistic experiments reveal that photoinduced single-electron transfer facilitates the generation of silyl radicals, which engage in regioselective addition to the alkyne before hydrogen atom abstraction completes the cycle. Another breakthrough demonstrates an iridium-catalysed protocol employing tailor-made N-heterocyclic carbene ligands to achieve enantioselective dehydrogenative silylation of prochiral propargylic alcohols. The method delivers chiral siloxyalkynes with excellent enantiomeric excess, opening new avenues for asymmetric synthesis. These contributions underscore the growing importance of combining photochemical activation and ligand engineering to surmount selectivity barriers in silylation chemistry.

Dehydrogenative Silylation of Terminal Alkynes publication trend

The graph below shows the total number of articles in dehydrogenative silylation of terminal alkynes across all publications each year (not limited to Nature Index journals).

Technical terms

Dehydrogenative silylation: A reaction coupling a silane with an alkyne, eliminating hydrogen gas to form a new carbon–silicon bond.

Terminal alkyne: An alkyne in which the carbon–carbon triple bond is located at the end of a carbon chain, bearing an acidic hydrogen.

Hydrosilane: A silicon compound containing direct silicon–hydrogen bonds, used as a silyl group donor.

Alkynylsilane: An organosilicon compound featuring a carbon–silicon bond directly adjacent to a carbon–carbon triple bond.

References

1. Carboxylate-Catalyzed C‑Silylation of Terminal Alkynes. Organic Letters (2024).
2. Cobalt‐Catalyzed Dehydrogenative C−H Silylation of Alkynylsilanes. Chemistry - A European Journal (2021).