2-Diazo-1,3-dimesityl-2H-indene and 1,3-dimesitylisoindenylidene
摘要:
Reduction of 1,3-dihydroxy-1,3-dimesitylindan-2-one oxime 5 with Hl-HOAc gives the primary enamine, 2-amino-1,3-dimesitylindene 7. This resists hydrolysis to 1,3-dimesitylindan-2-one 6 even with boiling concentrated HCl-dioxane (1:1); steric protection of C-3 by the mesityl group and an overwhelming preference for the enamine tautomer may account for the unusual stability of 7. With NaNO2-HOAc 7 gives 2-diazo-1,3-dimesityl-2H-indene 2, the only known 2-diazoindene. The C-13 and N-15 NMR shifts of C-2 and the terminal nitrogen in 2 suggest somewhat greater diazonium indenylide character than for 1-diazoindene. Though isolable, 2 decomposes slowly at 20-degrees-C or upon exposure to visible light to give the hydrocarbons 14, 15 and 16, which probably arise via 1,3-dimesitylisoindenylidene 3 and the o-quinodimethanes 18 and 19. The decomposition of 2 in the presence of oxygen, 4-phenyltriazoline-3,5-dione, and N-phenylmaleimide are described.
Preparation, thermolysis, and photolysis of 2-diazo-1,3-dimesityl-2H-indene: a sterically stabilised 2-diazoindene
作者:David W. Jones、Alan Pomfret
DOI:10.1039/c39820000919
日期:——
2-Diazo-1,3-dimesityl-2H-indene (2) is prepared by reaction of 2-amino-1,3-dimesityl-2H-indene with sodium nitrite–acetic acid; though isolable (2) decomposes either thermally (20 ° C) or on exposure to visible light to give the hydrocarbons (6), (7), and (8) derived via the carbene (9) and the o-quinodimethane (10).
alcohols with aryl nucleophiles were studied. Highly selective and tunable synthetic methods were developed for one-pot formation of either triaryl-allenes, diaryl-indenes or tetraaryl-allyl target products by appropriate reaction conditions (time, temperature, catalyst, substrate, nucleophile, solvent). Corresponding 2-halo-indenes, appropriate for further Pd-catalyzed reactions, were also obtained