Magnesium‐Catalyzed Tandem Dehydrogenation‐Dehydrocoupling: An Atom Economical Access to Alkynylboranes

• Published in: Chemistry : a European journal Vol. 26; no. 15; pp. 3236 - 3240
• Main Authors: Birepinte, Mélodie, Liautard, Virginie, Chabaud, Laurent, Pucheault, Mathieu
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 12.03.2020; Wiley Subscription Services, Inc; Wiley-VCH Verlag
• Subjects: Alkynes; alkynylboranes; aminoboranes; Boranes; Chemical Sciences; Chemistry; Chemistry, Multidisciplinary; dehydrocoupling; Dehydrogenation; Magnesium; Organic chemistry; Physical Sciences; Room temperature; Salts; Science & Technology; ROOM-TEMPERATURE; HYDROBORATION; ACIDS; dehydrocoupling; BOND-FORMING REACTIONS; REACTIVITY; magnesium; TERMINAL ALKYNES; AMINE-BORANE COMPLEXES; PINACOLBORANE; HYDRIDE; alkynylboranes; aminoboranes; dehydrogenation; C-H BORYLATION
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201905772

Owing to the unusual reactivity of sterically hindered amine–borane complexes, a catalytic system based on magnesium salts was designed to perform a tandem dehydrogenation–dehydrocoupling between terminal alkynes and boranes. The reaction is providing pure alkynylboranes within few minutes at room temperature, with only two molecules of hydrogen as a byproduct. A tandem made for two: An efficient synthesis of alkynylaminoborane was developed using a magnesium catalyst at room temperature. The reaction proceeds within few minutes in high yields releasing hydrogen through a tandem dehydrogenation/dehydrocoupling original mechanism between terminal alkynes and boranes.