Generation of Azines by the Reaction of a Nucleophilic Carbene with Diazoalkanes:  A Synthetic and Crystallographic Study

Abstract

Reactions of the nucleophilic carbene 1,3-dimesityl-imidazol-2-ylidene (1) with diazofluorene, diphenyldiazomethane, and azidotrimethylsilane were examined. Specifically, carbene 1 reacts with diazofluorene and diphenyldiazomethane to give addition products (azines: 3 and 4, respectively). Compounds 3 and 4 were further characterized in the solid-state by single-crystal X-ray crystallographic studies. [3 (a = 9.7936(6) A, b = 10.0529(7) A, c = 16.251(1) A, alpha = 75.765(1) degrees, beta = 79.711(1) degrees, gamma = 64.321(1) degrees, Z = 2, space group P1); 4 (a = 11.681(3) A, b = 11.861(4) A, c = 21.186(3) A, alpha = 90 degrees, beta = 97.05(2) degrees, gamma = 90 degrees, Z = 4, space group P2(1)/n)]. The structural parameters of 3 and 4 are discussed with reference to previously characterized symmetrical and unsymmetrical azines. Structural data suggest that charge separation is possible in 3.

Hyperpolarizability of donor–acceptor azines subject to push–pull character and steric hindrance

“…Thus, the azines 3h,q and 4-8 studied by Clyburne et al 28,29 can be confirmed to be strongly polarized, p-delocalized materials which, in case extreme push-pull substitutions, should exhibit NLO behaviour.…”

“…Synthesis and characterization of azines 3-8 are published [24][25][26][27][28][29] ; all calculations were carried out on SGI workstations and LINUX clusters.…”

“…22 In opposite to the triazene linkage (]N-N]N-), which does not act as a conjugation stopper, 22,23 different results have been published for the similar azine bridge. The basic query concerns the situation whether [24][25][26][27] or not 28,29 the linking ]N-N] group acts as a conjugation stopper by employing our approach. 19a,20 Therefore, several types of azines (Scheme 1) were theoretically studied at the DFT level of theory in which the linking azine unit should act either as conjugation stopper (3) [24][25][26][27] or show trends consistent with delocalization within the azine framework (3h, 3q, 4-7).…”

Synthesis and properties of heteroaromatic carbenes of the imidazole and triazole series and their fused analogues

“…Decomposition of carbene-azide adducts. 367 Analogues with donor and acceptor moieties on the molecule have also been obtained. 369 The azine fragment, depending on its substituents, can act as a conductor or breaker of the conjugation.…”

Efficient and Eco-Friendly Synthesis of Fluorenone Azines by Using Sulphated Titania Acid Catalyst

“…In recent years synthesis of organic compound has been use catalyst such as hexaaquaaluminium (III) tetrafluoroborate [2], ionic liquids [3] and modified zirconia [4] etc. Diimines (azines) are most required compounds; they are undergoing interesting reactions and applications [5]. Azine compounds have been used in medicinal and materials relevant applications such as anti-bacterial drugs [6], anti-malarial drugs [7] anti-fungal drugs [8], drug development [9], tumor growth inhibitors [10], optoelectronics [11], NLO [12] materials , light-control devices [13], organic semiconductors [14], tunable molecular devices [15].…”