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Hydroboration of terminal and internal alkynes has been carried out with extremely high efficiency by using a bench-stable and inexpensive cobalt( ii ) coordination polymer as a precatalyst in the presence of potassium tert -butoxide (KO t Bu). Good to high yields of alkenylboronate esters were obtained in 5–30 min with low catalyst loading (0.025 mol%). Good chemoselectivity for alkyne vs alkene hydroboration was observed. A possible catalytic cycle involving the in situ formation of an active Co–H species is proposed based on additional experimental results. This work provides valuable implications for the design of efficient and practical base metal catalysts.
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This content will become publicly available on March 26, 2026
Efficient and selective hydroboration of alkenes catalyzed by an air-stable PPCF3P)CoI2 precatalyst
Alkene hydroboration provides a convenient route to generate organoborane synthons and recent efforts to develop catalysts for this and many other organic transformations have involved a shift to Earth-abundant first row transition metals. Herein, we report the synthesis of a new bench-stable CoII precatalyst, (PPCF3P)CoI2 (1), which was found to function as a highly active alkene hydroboration catalyst in the presence of an activator. The substrate scope was probed through exploring a collection of electronically and sterically distinct alkenes with a wide range of substitution patterns and functional groups. A single species is spectroscopically observed during catalysis, and activation of the CoII precatalyst with KBEt3H in the presence of styrene and in the absence of HBpin affords this species, (PPCF3P)Co(h2-styrene)H (2), which has been isolated, characterized, and demonstrated to function as an active catalyst for alkene hydroboration in the absence of additional activators. A plausible mechanism involving a CoI-hydride active species is proposed based on catalytic and stoichiometric experiments.
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- PAR ID:
- 10600882
- Publisher / Repository:
- Chemical Science
- Date Published:
- Journal Name:
- Chemical Science
- Volume:
- 16
- Issue:
- 13
- ISSN:
- 2041-6520
- Page Range / eLocation ID:
- 5717-5725
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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