1372205-87-2Relevant academic research and scientific papers
Regiocontrolled CuI-catalyzed borylation of propargylic- functionalized internal alkynes
Moure, Abraham L.,Gomez Arrayas, Ramon,Cardenas, Diego J.,Alonso, Ines,Carretero, Juan C.
supporting information; experimental part, p. 7219 - 7222 (2012/06/16)
Good to excellent reactivity and regiocontrol have been achieved in the CuI-catalyzed borylation of dialkyl internal alkynes with bis(pinacolato)diboron. The presence of a propargylic polar group (OH, OR, SAr, SO2Ar, or NHTs), in combination with PCy3 as ligand, allowed maximizing the reactivity and site-selectivity (β to the propargylic function). DFT calculations suggest a subtle orbitalic influence from the propargylic group, matched with ligand and substrate size effects, as key factors involved in the high β-selectivity. The vinylboronates allowed the stereoselective synthesis of trisubstituted olefins, while allylic substitution of the SO2Py group without affecting the boronate group provided access to formal hydroboration products of unbiased dialkylalkynes.
