O. V. Ershov

Glycine catalyzed diastereoselective domino-synthesis of 6-imino-2,7-dioxabicyclo[3.2.1]octane-4,4,5-tricarbonitriles in water

The first example of glycine-catalyzed direct domino synthesis of 6-imino-2,7-dioxabicyclo[3.2.1]octane-4,4,5-tricarbonitriles in aqueous medium is described, giving products in excellent yields and moderate to excellent diastereoselectivities. This approach provides a highly efficient and environmentally benign access to cyano-substituted 2,7-dioxabicyclo[3.2.1]octane.

Reaction of α,β-unsaturated ketones with tetracyanoethylene

Abstract Reaction of tetracyanoethylene with α,β-unsaturated ketones was investigated. 3-R1-4-R2-6-R3-5-oxo-1,1,2,2-cyclohexanetetracarbonitriles, unsaturated tetracyanoalkanones, 3-R-5,5-dihydroxy-1,1,2,2-cyclohexanetetracarbonitriles, 1,2,2-tricyano-3-R-5-oxo-1-cyclohexanecarboxamides, 3-R1-4-R2-8-R3-5-hydroxy-7-oxo-6-azabicyclo[3.2.1]octane-1,2,2-tricarbonitriles were synthesized.

Synthesis of photochromic 5,6-diaryl-2-chloropyridine-3,4-dicarbonitriles from 3,4-diaryl-4-oxobutane-1,1,2,2-tetracarbonitriles

We now propose a new synthetic approach to photochromic diarylethenes, which is based on the reaction of tetracyanoethylene with ketones as key intermediate step. Tetracyanoethylation of ketones has been well documented; however, there are almost no published data on reactions of aryl arylmethyl ketones with tetracyanoethylene. Adducts of tetracyanoethylene with ketones of the general formula R(CO)CH2R′ were used as starting compounds to obtain heterocycles containing an RC=CR′ fragment [4–10]. Analogous reactions with aryl arylmethyl ketones Ar(CO)CH2Ar could give rise to various 1,2-diarylethenes as new potential photochromes. We were the first to react tetracyanoethylene with 1,2-diarylethanones Ia and Ib in the presence of a catalytic amount of hydrochloric acid. As a result, we isolated 3,4-diaryl-4-oxobutane-1,1,2,2-tetracarbonitriles IIa and IIb. The substrates were deoxybenzoin (Ia), the parent compound of the 1,2-diarylethanone series, and 1,2-bis(2,5-dimethylthiophen-3-yl)ethanone (Ib). The latter was selected taking into account that diarylethenes containing thienyl substituents are most promising from the viewpoint of the design of practically useful photochromic devices [1]. Ketone Ib was synthesized in a number of steps starting from hexane2,5-dione [11].

Domino-synthesis and fluorescence properties of 4-cyano-2-oxo-1,2-dihydropyridine-3-carboxamides and 2-oxo-1,2-dihydropyridine-3,4-dicarbonitriles

Non-catalytic conversion of 4-oxoalkane-1,1,2,2-tetracarbonitriles in the presence of water leads to the formation of a mixture of fluorescent 4-cyano-2-oxo-1,2-dihydropyridine-3-carboxamides and 2-oxo-1,2-dihydropyridine-3,4-dicarbonitriles in equal proportions. This transformation was explained, spectral-luminescence properties were investigated, and fluorescence quantum yield was measured.

Directed synthesis of new spiro-fused photochromes of diarylethene series

The reaction of tetracyanoethylated 1,2-diarylethanones with morpholine was used for directed synthesis of spiro-fused diarylethenes, 8-amino-1-imino(oxo)-6-morpholino-2-oxa-7-azaspiro[4.4]nona-3,6,8-triene-9-carbonitriles. The intermediates in this process were tetracyanoalkanone salts. The formation of spiranes was sensitive to the nature of aromatic substituents at the carbonyl group of 3,4-diaryl-4-oxobutane-1,1,2,2-tetracarbonitriles. The obtained spiro-fused diarylethenes exhibited photochromic properties.

Three-component synthesis of 2-chloropyridine-3,4-dicarbonitriles

According to published data, tetracyanoethylene reacts with ketones in the presence of a catalytic amount of hydrochloric acid to give 4-oxoalkane1,1,2,2-tetracarbonitriles [1, 2]. It is also known that concentrated hydrochloric acid reacts with 4-oxoalkane-1,1,2,2-tetracarbonitriles to produce 2-chloropyridine-3,4-dicarbonitriles [3]. These data suggest that 2-chloropyridine-3,4-dicarbonitriles could be prepared via one-pot procedure, i.e., without isolation of 4-oxoalkane-1,1,2,2-tetracarbonitriles, which should make their preparation simpler and less expensive.

Heterocyclization of michael adducts of β-diketones with arylmethylidene derivatives of malononitrile dimers

Reaction of arylmethylidene derivatives of malononitrile dimer with 1,3-cyclohexanediones in anhydrous methanol in the presence of sodium methylate as catalyst affords 4-amino-5-aryl-2-methoxy-6-oxo-5,6,7,8,9,10-hexahydrobenzo[b][1,8]naphthyridine-3-carbonitrile. In the presence of strong electron-donor substituents in the benzene ring the reaction takes another route resulting in 4-amino-2-aryl-6-methoxypyridine-3,5-dicarbonitriles.

Spiro heterocyclization of 4-aryl-4-oxobutane-1,1,2,2-tetracarbonitriles to 3H-pyrrole derivatives, 2-oxa-7-azaspiro[4.4]nona-3,6,8-trienes

Abstract4-Aryl-3-methyl-4-oxobutane-1,1,2,2-tetracarbonitriles reacted with morpholine to give 8-amino-3-aryl-1-imino-4-methyl-6-(morpholin-4-yl)-2-oxa-7-azaspiro[4.4]nona-3,6,8-triene-9-carbonitriles.

A novel method for the domino synthesis of 6-imino-2,7-dioxabicyclo[3.2.1]octane-4,4,5-tricarbonitriles and studies of stereochemical characteristics of formation and structure thereof

A novel universal method for the preparative synthesis of 6-imino-2,7-dioxabicyclo[3.2.1]octane-4,4,5-tricarbonitriles was developed, previously unknown 1- and 8-aryl-substituted derivatives were synthesized, stereochemical characteristics of this transformation were studied, and the reasons for its diastereoselectivity were identified.

The synthesis of 3-amidinio-2-aminopyridine-4-carboxylates

Abstract A new class of isonicotinic acid derivatives, 3-amidinio-2-aminopyridine-4-carboxylates, from aqueous ammonia and β,β,γ,γ-tetracyanoalkanones, is reported.