Transition Metal‐Free Regio‐ and Stereo‐Selective trans Hydroboration of 1, 3‐Diynes: A Phosphine‐Catalyzed Access to (E)‐1‐Boryl‐1, 3‐Enynes. Issue 63 (1st September 2022)

• Record Type: Journal Article
• Authors: Jos, Swetha; Szwetkowski, Connor; Slebodnick, Carla; Ricker, Robert; Chan, Ka Lok; Chan, Wing Chun; Radius, Udo; Lin, Zhenyang; Marder, Todd B.; Santos, Webster L.
• Is Part Of: Chemistry. Volume 28:Issue 63(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-01
• Subjects: enediyne -- enyne -- hydroboration -- organocatalytic -- stereoselective; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202202349
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: We report a transition metal‐free, regio‐ and stereo‐selective, phosphine‐catalyzed method for the trans hydroboration of 1, 3‐diynes with pinacolborane that affords ( E )‐1‐boryl‐1, 3‐enynes. The reaction proceeds with excellent selectivity for boron addition to the external carbon of the 1, 3‐diyne framework as unambiguously established by NMR and X‐ray crystallographic studies. The reaction displays a broad substrate scope including unsymmetrical diynes to generate products in high yield (up to 95 %). Experimental and theoretical studies suggest that phosphine attack on the alkyne is a key process in the catalytic cycle. Abstract : A transition metal‐free method for the trans‐ hydroboration of 1, 3‐diynes to afford ( E )‐1‐boryl‐1, 3‐enynes is reported. Boron adds to the external carbon of the diyne framework. Experimental and DFT studies suggest that phosphine attack on the diyne is a key step in the catalytic cycle.