Zur reaktion von cyclopropenonen mit azomethinen VI

Pyrrolo[2,1-a]isoquinolines (review)

“…The analogous reaction of the isoquinoline (LXVIII) with diphenylcyclopropenethione [145] and also the reaction of diphenylcyclopropenone and the corresponding thione with 3,4-dihydroisoquinoline [146] are known. The reactions of 3,4dihydroisoquinoline with diphenylcyclopropenone and thiafulvene have also been investigated [147].…”

Catalyst‐Free [3+2] Cycloaddition of Unactivated Imines with Cyclopropenones

“…Cyclopropenones‐based annulations have been widely used in the construction of N‐, O‐, and S‐containing heterocycles since the first synthesis of cyclopropenone has been reported . Owing to the unique reactivity of cyclopropenones, many cyclization reactions have been designed for preparation of structurally complicated molecules, such as [3+2],– [3+3] and domino cyclization‐cyclization sequence etc.. As we have been focusing on the synthesis of nitrogen‐containing heterocyclic compounds with unactivited imines, we become interested in the easy assembly of polycyclic azacycles by the ring expanding reaction with cyclopropenones.…”

Unusual reactivity of thiosemicarbazides towards 2,3-diphenylcyclopropenone: synthesis of new pyridazinethiones and 1,2,4-triazolo[4,3-b]pyridazinethiones

“…8 Diphenylcyclopropenone (1) has been found to react with a wide range of imines and other compounds containing the C=N moiety, usually to form azacyclopentenones (pyrrolinones) via formal [2+3] cycloaddition reactions. [9][10][11][12][13][14] By contrast, the reaction of 1 with guanidine and its alkyl and/or aryl derivatives gave the corresponding 5,6-dihydro-4(1H)-pyrimidinone via a formal [3+3] cycloaddition reaction. 15 In general, cyclopropenone is amphiphilic, reacting readily with both nucleophilic and electrophilic reagents.…”

“…Moreover, cyclopropenones are strained ring ambident electrophiles with a tendency to form ring opened products, their reaction with nucleophiles has the possibility of carbonyl or conjugate addition. [9][10][11][12][13][14][15][16][17] Recently, we have found that the reactions of aroylphenylthioureas with 1 in acetic acid afforded the diasteromers of 3-(3 \ -aroyl-1-substituted-thioureido)-2,3-diphenylcinnamic acids. 18 Generally, the N 2 of thiosemicarbazides is described as a softer nucleophilic center than the harder and powerful terminal nitrogen N 1 .…”