作者: James F. Dunne , D. Bruce Fulton , Arkady Ellern , Aaron D. Sadow
DOI: 10.1021/JA108881S
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摘要: Coordinatively saturated ToMMgMe (1; ToM = tris(4,4-dimethyl-2-oxazolinyl)phenylborate) is an active precatalyst for intramolecular hydroamination/cyclization at 50 °C. The empirical rate law of −d[substrate]/dt k′obs[Mg]1[substrate]1 and Michaelis−Menten-type kinetics are consistent with a mechanism involving reversible catalyst−substrate association prior to cyclization. resting state the catalyst, ToMMgNHCH2CR2CH2CH═CH2 [R Ph, Me, —(CH2)5—], isolable, but isolated magnesium amidoalkene does not undergo unimolecular cyclization However, addition trace amounts substrate allows occur. Therefore, we propose two-substrate, six-center transition concerted C—N bond formation N—H cleavage as turnover-limiting step catalytic cycle.