Katsuma Y, Tsukahara N, Wu L, Lin Z, Yamashita M. Reaction of B
2 (o-tol)
4 with CO and Isocyanides: Cleavage of the C≡O Triple Bond and Direct C-H Borylations.
Angew Chem Int Ed Engl 2018;
57:6109-6114. [PMID:
29573087 DOI:
10.1002/anie.201800878]
[Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/14/2018] [Indexed: 01/12/2023]
Abstract
The reaction of highly Lewis acidic tetra(o-tolyl)diborane(4) with CO afforded a mixture of boraindane and boroxine by the cleavage of the C≡O triple bond. 13 C labeling experiments confirmed that the carbon atom in the boraindane stems from CO. Simultaneously, formation of boroxine 3 could be considered as borylene transfer to capture the oxygen atom from CO. The reaction of diborane(4) with t Bu-NC afforded an azaallene, while the reaction with Xyl-NC furnished cyclic compounds by direct C-H borylations.
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