Reaction of Enamines with Quinones

Reaction of Quinones with Nitrosoarenes

Formation of the 2,3-dicyanohydroquinone (3) can be rationalised in terms of preferential addition of cyanide at the most electron deficient unsubstituted carbon of the cyanoquinone (2 ) in the same way as alcohols and other nucleophiles add to the 3-position of the acylquinone ( 8 ) [4], However, such an argu­ ment could not be applied to the formation of the dihydroxylamine (6 ). Hence, eithe...

Reaction of heterocyclic enamines with nitrile oxide and nitrilimine precursors.

Alkylidenepyrrolidines 1, 21, 24 and 26 undergo reactions with nitrile oxides and nitrilimines or their precursors to give a range of novel heterocyclic compounds. With alkylidenepyrrolidine ester 1, nitrolic acids give products in which the liberated nitrous acid reacts with the alkylidenepyrrolidine, followed by two cycloadditions to give adducts 3. In contrast, hydroximoyl chlorides give iso...

Vibrational Properties of Quinones in Photosynthetic Reaction Centers

Fourier transform infrared difference spectroscopy (FTIR DS) is widely used to study the structural details of electron transfer cofactors in photosynthetic protein complexes. In photosynthetic proteins quinones play an important role, functioning as a cofactor in light-driven electron transfer. In photosystem I (PS I) phylloquinone (PhQ) functions as an intermediary in electron transfer. To in...

Crane-quinones with Coenzyme

4. CRANE, F. L., LESTER, R. L., WIDMER, C. and HATEFI, Y. Studies on the electron transport system XVIII. Isolation of coenzyme Q from beef heart and beef heart mitochondria. Biochim. Biophys. Acta 32: 73-79. 1959. 5. CRANE, F. L., WIDMER, C., LESTER, R. L. and HATEFI, Y. Studies on the electron transport system XV. Coenzyme Q (Q275) and the succinoxidase activity of the electron transport part...

Stereoselective intermolecular formal [3+3] cycloaddition reaction of cyclic enamines and enones.