Anlagerung von Diazobenzolimid an Chinone

Highly Regio‐ and Diastereoselective Chromium(0)‐Catalysed Cyclopropanation of 1‐Alkoxy‐1,3‐dienes with Diazo Compounds

“…The catalytic system involving 9-diazo-9H-fluorene (2) and the (cis-cyclooctene)chromium(0) complex 1 has been successfully applied to electron-rich dienes. The [2ϩ1]-cycloaddition proceeds in a highly regioselective way at the unsubstituted 3-position of the conjugated dienes to furnish the corresponding cyclopropanes in good to excellent yields.…”

“…Since the early research results of Loose [1] and Wolff, [2] who observed that the decomposition temperatures of diazo ketones and diazoacetic esters were significantly lowered by the presence of copper powder, cupric sulfate or silver salts, the catalytic decomposition of diazo compounds to form reactive carbenes has become a standard method in organic synthesis. For example, it is used in CH insertions, OH insertions, the cyclopropanation of olefins and the Buchner reaction.…”

Electrochromics by Intramolecular Redox Switching of Single Bonds

“…Hydrazone 6 [7] smoothly reacted with cyclooctane-1,5-dione (7) to afford the pale yellow bis(azine) RED-8 in 73% yield (Scheme 2).…”

“…[7] , Michler's ketone (30.0 g, 0.11 mol), hydrazine (47.0 g, 87% in water, 0.78 mol), and ethanol (20 mL) were heated to 200°C in an autoclave (glass, applicable to 10 bar) for 24 h. On slow cooling and stirring, crystals deposited and were separated and washed with ice-cold ethanol (20 mL). 24.8 g (80%) pure 6, m.p.…”

Some reactions of ethyl azidoformate with quinones

“…The reactions of azides with conjugated systems have been investigated by various workers (1)(2)(3)(4)(5)(6). The addition of an azide moiety to the double bond initially forms a triazoline derivative which may be stable or undergo oxidation to a triazole (3).…”