Nitration of Heteroaryltrimethyltins by Tetranitromethane and Dinitrogen Tetroxide: Mechanistic Aspects, Scope and Limitations

Abstract

The nitration of 2‐(trimethylstannyl)heteroarenes by tetranitromethane (TNM) or dinitrogen tetroxide has been shown to be possible when the HOMO energy of the heteroaryltin is high enough to allow the formation of the corresponding radical cation. The reaction proceeds through a charge‐transfer complex between heteroaryltin and TNM, followed by a single‐electron transfer, which is enhanced under sunlamp irradiation. Accordingly, 2‐nitrobenzo[b]furan, 2‐nitrobenzo[b]thiophene, 2‐nitropyridine and 2‐nitroindoles were obtained by this method. However, the nitration of 2‐stannylated pyrimidine or of stannylated 1,3,5‐triazines has been shown to be impossible, due to the low energy of their HOMO orbitals. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

The correlation consistent composite approach (ccCA): An alternative to the Gaussian-n methods

“…Tetranitromethane ͑TNM͒ can be used as a reagent for photonitration, for example, in syntheses of high-energy materials 91 or the heterocyclization of alkenes. 92 Early infrared 93 and electron gas diffraction studies 94,95 showed the structure of TNM to possess S 4 point group symmetry.…”

A Tris‐Cyclometalated Iridium(III) Complex of 2‐(5,5‐Dioxido‐dibenzothiophen‐3‐yl)pyridine: Synthesis, Structural, Redox and Photophysical Properties

“…Ligand 6 was readily prepared by Stille [14] reaction of 3-bromodibenzothiophene S,S-dioxide 4 [15] with commercially available 2-tris(n-butyl)stannylpyridine (5) [16] in moderate yield (58 %). An excess of ligand 6 was then treated with Ir(acac) 3 in glycerol at 220°C [17] to give the fac-triscyclometalated iridium(III) complex 3 in 82 % yield.…”

Carbon‐metalated triazines and tetrazines: Synthesis and reactivity

“…[37][38][39][40][41] Unusable complex mixtures of products were obtained from the attempted reactions of n-Bu 3 SnLi with cyanuric chloride or 2,4-dichloro-6-phenoxy-1,3,5-triazine in various conditions. [42] In particular, the formation of n-Bu 3 SnCN was identified by GC/MS. Interaction of cyanuric tribromide 119 with hexamethyl ditin in the presence of a catalytic amount of Pd 0 in benzene media in a sealed tube at 150 C was also investigated (Scheme 25).…”

“…Interaction of cyanuric tribromide 119 with hexamethyl ditin in the presence of a catalytic amount of Pd 0 in benzene media in a sealed tube at 150 C was also investigated (Scheme 25). [42] This process resulted in formation of a mixture of products of free-radical insertion and self-fragmentation, among which stannyl-, methyl-, and cyanosubstituted 1,3,5-triazines 120 to 124 were identified (Scheme 25).…”