Diaziridine ring expansion in 6-aryl-1,5-diazabicyclo[3.1.0]hexanes on treatment with nitriles assisted by ionic liquids

Insertion of carbon disulfide and the nitrile group into the diaziridine ring of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes in ionic liquids catalyzed by BF3 · Et2O

“…The complete conversion of diaziridine 1a in acetonitrile was achieved within 10 days; in the ionic liquid, within 4 days; upon heating without a solvent in the presence of BF 3 •Et 2 O, within 25 days. However, instead of expected compounds 3 or 5, all reactions pro duced 3,4 di(2 phenylethyl) 1,3,4 thiadiazolidine 2,5 dithione (9) in similar yields (30-35%). 3,4 Disubsti tuted 1,3,4 thiadiazolidine 2,5 dithiones were described in the literature.…”

Reaction of 1-arylmethylidenepyrazolidin-1-azomethine imines with aryl ketenes

“…These reactions were success fully accomplished only in ionic liquids, that allowed us to develop simple methods for the preparation of a number of bicyclic structures 7-10 (Scheme 2). [16][17][18][19] The present work is devoted to the study of a possibility of condensation of azomethine imines 1, generated in situ from 6 aryl 1,5 diazabicyclo[3.1.0]hexanes 4 under con ditions found earlier, 15-19 with aryl ketenes 11 in order to obtain 3,4 diaryl(3,3,4 triaryl) 1,5 diazabicyclo[3.3.0] octan 2 ones 12, new γ lactam azaanalogs (Scheme 3).…”

“…[16][17][18][19] Azomethine imine 1a was generated upon the action of BF 3 •Et 2 O in catalyt ic amounts (0.1 mmol) on the starting compound 4a (0.3 mmol) in MeCN or ionic liquid (IL), then phenyl acetyl chloride and Et 3 N were added simultaneously drop wise at reduced temperature. However, in this case too the reaction took similar direction only at considerably higher rate, and 1,2 bis(phenylacetyl)pyrazolidine 19 was isolat ed in low yield as the reaction product independent on the structure of compound 4a-c involved into the reaction.…”

A new reaction of 1,2‐di‐ and 1,2,3‐trialkyldiaziridines: Ring expansion under the action of diethyl acetylenedicarboxylate in ionic liquids

“…Arylketenes [3–6], aroyliso‐ and aroylisothiocyanates [7, 8], carbon disulfide [9, 10], and activated nitriles [10, 11] were investigated as dipolarophiles. Thus, the reaction of arylketenes with 1,2‐dialkyldiaziridines 1 resulted in 5‐aryl‐1,3‐dialkylimidazolidin‐4‐ones 3 and with 1,5‐diazabicyclo[3.1.0]hexanes 2— in heterocyclic compounds of two kinds—1‐(arylacetyl)pyrazolidines 4 and 1,5‐diazabicyclo[3.3.0]octan‐2‐ones 5 (Scheme ).…”

“…However, these researches showed that new heterocyclic systems in common organic solvents could only be achieved in reactions with highly reactive reagents—arylketenes [3–6] and aroylisocyanates [7]. A reaction between diaziridines 1 and 2 and the other foresaid reagents was also performed successfully though only with ionic liquids (ILs) used as a reaction medium [8–11]. Moreover, absolutely unexpected heterocyclic structures were built in those solvents in some cases.…”