Wang T, Wang L, Daniliuc CG, Samigullin K, Wagner M, Kehr G, Erker G. CO/CO and NO/NO coupling at a hidden frustrated Lewis pair template.
Chem Sci 2017;
8:2457-2463. [PMID:
28451352 PMCID:
PMC5369402 DOI:
10.1039/c6sc04459j]
[Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/26/2016] [Indexed: 01/21/2023] Open
Abstract
N-Allyltetramethylpiperidine is readily isomerized to the corresponding enamine by treatment with catalytic amounts of B(C6F5)3. It adds HB(C6F5)2 at the nucleophilic enamine carbon atom to form a C/B Lewis adduct. This reacts with two molar equivalents of carbon monoxide by selective head to tail coupling to give a five-membered C2O2B heterocycle. In contrast the enamine/HB(C6F5)2 Lewis pair reacts with two molar equiv. of nitric oxide by head to head coupling. This reaction probably proceeds via equilibrium with the corresponding vicinal N/B Lewis pair. Most products were characterized by X-ray diffraction.
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