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In heterogeneous catalysis, the catalyst is in a different phase from the reactants. name: 5-Nitroquinoxaline, At least one of the reactants interacts with the solid surface in a physical process called adsorption in such a way. 18514-76-6, name is 5-Nitroquinoxaline. In an article£¬Which mentioned a new discovery about 18514-76-6
A small-ring phosphacycloalkane (1,2,2,3,4,4-hexamethylphosphetane, 3) catalyzes intramolecular C-N bond forming heterocyclization of o-nitrobiaryl and -styrenyl derivatives in the presence of a hydrosilane terminal reductant. The method provides scalable access to diverse carbazole and indole compounds under operationally trivial homogeneous organocatalytic conditions, as demonstrated by 17 examples conducted on 1 g scale. In situ NMR reaction monitoring studies support a mechanism involving catalytic PIII/PV=O cycling, where tricoordinate phosphorus compound 3 represents the catalytic resting state. For the catalytic conversion of o-nitrobiphenyl to carbazole, the kinetic reaction order was determined for phosphetane catalyst 3 (first order), substrate (first order), and phenylsilane (zeroth order). For differentially 5-substituted 2-nitrobiphenyls, the transformation is accelerated by electron-withdrawing substituents (Hammett factor I = +1.5), consistent with the accrual of negative charge on the nitro substrate in the rate-determining step. DFT modeling of the turnover-limiting deoxygenation event implicates a rate-determining (3 + 1) cheletropic addition between the phosphetane catalyst 3 and 2-nitrobiphenyl substrate to form an unobserved pentacoordinate spiro-bicyclic dioxazaphosphetane, which decomposes via (2 + 2) cycloreversion giving 1 equiv of phosphetane P-oxide 3¡¤[O] and 2-nitrosobiphenyl. Experimental and computational investigations into the C-N bond forming event suggest the involvement of an oxazaphosphirane (2 + 1) adduct between 3 and 2-nitrosobiphenyl, which evolves through loss of phosphetane P-oxide 3¡¤[O] to give the observed carbazole product via C-H insertion in a nitrene-like fashion.
I hope this article can help some friends in scientific research. I am very proud of our efforts over the past few months and hope to 18514-76-6, help many people in the next few years.name: 5-Nitroquinoxaline
Reference£º
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N888 | ChemSpider