
Published: Feb. 12, 2024
The commercial reagent, HSi(OEt)3, was an efficient catalyst for the synthesis of E-alkenylboronate esters and alkyl gem-diboronate by single or double hydroboration terminal alkynes with HBPin (pinacolborane). reaction time controlled whether a addition to occurred. Aromatic containing strong electron-donating -withdrawing substituents at different positions as well aliphatic were efficiently mono- dihydroborated. Mechanistic studies suggested that formation diboronate proceeds second cycle being rate determining. HSi(OEt)3 has been identified deactivation pathway operative in catalysis. Screening other silicon compounds this transformation supported steric electronic profile is key promote step.
Language: Английский