Syntheses of heterocyclic compounds. Part XXIV. Cyclisation studies with ortho-substituted arylcarbene and arylnitrene precursors
作者:G. V. Garner、D. B. Mobbs、H. Suschitzky、J. S. Millership
DOI:10.1039/j39710003693
日期:——
indolines. The scope and mechanism of this cyclisation have been explored. Moreover, benzaldehyde tosylhydrazones with o-alkoxy-, o-thioalkyl-, and o-phosphonate substituents as well as the corresponding diazoalkanes were pyrolysed and photolysed. The products from these carbene precursors were compared with those obtained from the analogous nitrene precursors [i.e. ArN3 or ArNO2+(RO)3P].
inexpensive chromium(II) chloride as precatalyst, accompanied by an imino auxiliary, the selective arylative and alkylative C–C coupling of C(aryl)–N bonds can be achieved. Crossover experiments indicate that a low-valent chromium species, formed in situ by reduction of CrCl2 with Grignard reagent, is responsible for the catalytic cleavage of C(aryl)–N bonds. DFT calculations show that facile insertion of the
Synthesis of spiro[imidazole-4,3'-quinolin]ones from [2-(dimethylamino)benzylidene]-2-(methylsulfanyl)imidazolones
作者:Elvira R. Zaitseva、Alexander Yu. Smirnov、Nadezhda S. Baleeva、Mikhail S. Baranov
DOI:10.1007/s10593-021-02969-5
日期:2021.6
5-[2-(dimethylamino)benzylidene]-3-methyl-2-(methylsulfanyl)-3,5-dihydro-4H-imidazol-4-ones with catalytic amounts of scandium triflate resulted in a [1,5]-hydride shift followed by cyclization, giving 1,1'-dimethyl-2-(methylsulfanyl)-1',4'-dihydro-2'Hspiro[imidazole-4,3'-quinolin]-5(1H)-ones. All of the newly synthesized compounds containing various substituents in the benzylidene moiety were isolated
用催化量的三氟甲磺酸钪处理 5-[2-(二甲氨基)苯亚甲基]-3-甲基-2-(甲基硫烷基)-3,5-二氢- 4 H -咪唑-4-酮导致 [1, 5]-氢化物转移,然后环化,得到 1,1'-二甲基-2-(甲基硫烷基)-1',4'-二氢-2' H螺[咪唑-4,3'-喹啉]-5(1 H)-那些。所有在亚苄基部分含有各种取代基的新合成化合物均以良好的产率分离。