Organoboron compounds Communication 402. Structure of the products of the reaction of N2-Diisopropylboryl-N1-alkylbenzamidines with phenyl isonitrile

Conclusions The reaction of N²-diisopropylboryl-N¹-alkylbenzamidines with phenyl isonitrile leads to 1-alkyl-2-phenyl-4,4-diisopropyl-5-phenylimino-1-aza-3-azonia-4-borata-2-cyclopentenes. The structures of these products were demonstrated using x-ray diffraction structural analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2370–2375, October, 1982.     

Synthesis of 12-aryl-1-oxo-1,2,3,4,5,12-hexahydroindolo-[2,1-b]quinazoline-6-carbonitriles by recyclization of 11-aryl-1-oxo-2,3,4,5,10b,11-hexahydro-1H-indolo[2,3-b]quinoline-10b-carbonitriles

A general and convenient method for the synthesis of 12-aryl-1-oxo-1,2,3,4,5,12-hexahydroindolo[2,1-b]quinazoline-6-carbonitriles was proposed. The method is based on the recyclization of 11-aryl-1-oxo-2,3,4,5,10b,11-hexahydro-1H-indolo[2,3-b]quinoline-10b-carbonitriles. The structure of 12-(3-methoxyphenyl)-8-methyl-1-oxo-1,2,3,4,5,12-hexahydroindolo[2,1-b]quinazoline-6-carbonitrile was studied by X-ray diffraction analysis.     

Photochromic Dihetarylethenes: XX. Synthesis and Photochromic Properties of Dithienylethenes with a Fixed Conformation

>A procedure was developed for the synthesis of bis(2,5-dimethyl-3-thienyl)ethenes with partially fixed molecular conformation, and their photochromic properties in solution were studied. The structure of photochromic 1-(2,5-dimethyl-3-thienyl)-7,9-dimethyl-5,6-dihydrothieno[3',4' : 3,4]pyrido[1,2-c][1,3]oxazol-3-one, as well as of 1-(2,5-dimethyl-3-thienyl)-7,9-dimethylthieno[3',4' : 3,4]pyrido[1,2-c][1,3]oxazol-3-one possessing no photochromic properties, was determined by X-ray analysis.     

Nitropyridines: X. Palladium-catalyzed cross-coupling of 2-bromo-5-nitropyridine with terminal acetylenes

Substituted 5-nitro-2-ethynylpyridines were synthesized by the Sonogashira reaction of 2-bromo-5-5-nitropyridine with terminal acetylenes. Desilylation, oxidative decarbonylation, and the retro-Favorskii reaction of the cross-coupling products of 2-bromo-5-nitropyridine with trimethylsilylacetylene, prop-2-ynyl alcohol, and 2-methylbut-3-yn-2-ol, respectively, gave 2-ethynyl-5-nitropyridine. The hydration of 2-ethynyl-5-nitropyridine and 5-nitro-2-(phenylethynyl)pyridine according to Kucherov afforded 2-acetyl-5-nitropyridine and 5-nitro-2-phenacylpyridine, respectively.     

Photochromic dihetarylethenes. 6. Photochromic derivatives of thieno[3,2-b]thiophene

1,2-Bis{5-(2-benzothiazolyl)-2-methyl-6-trifluoromethylthieno[3,2-b]thiophen-3-yl}hexafluorocyclopentene possessing high fatigue resistance was synthesized for the first time. Its photochromic and fluorescence properties were studied. The structure of its cyclic form was established by X-ray diffraction analysis.