The reaction of cyclohexyl isocyanide and dimethyl acetylenedicarboxylate with o- and p-quinones: a novel synthesis of iminolactones

A three-component synthesis of functionalized ketenimines by the reaction of alkyl isocyanides and dialkyl acetylenedicarboxylates in the presence of 2-quinolinol

“…Of special interest is the strong ketenimine absorption band at about 2079 cm -1 . Based on the wellestablished chemistry of isocyanides, [19][20][21][22] it is reasonable to assume that 4 and 5 result from an initial addition of the alkyl isocyanide to the acetylenic ester and subsequent protonation of the 1:1 adduct by the NH-acid. Then, the positively charged ion 7 can be attacked at two positions by the nitrogen atom of the anion of the NH-acid.…”

One-pot synthesis of highly functionalized stable ketenimines of 2,2,2-trifluoro-N-aryl-acetamides

“…On the basis of the well-established chemistry of isocyanides [29][30][31][32][33], it is reasonable to assume that the functionalized ketenimine 4 results from the initial addition of the isocyanide to the acetylenic ester and subsequent protonation of the 1:1 adduct 5 by 2,2,2-trifluoro-Nphenyl-acetamide. Then, the positively charged ion 6 is attacked by anion 7 to give the product 4 (Scheme 2).…”

Reaction between isocyanides and dialkyl acetylenedicarboxylates in the presence of 4,5-diphenyl-1,3-dihydro-2H-imidazol-2-one. One-pot synthesis of 5H-imidazo[2,1-b][1,3]oxazine derivatives

“…On the basis of the well-established chemistry of isocyanides, [16][17][18][19][20] it is reasonable to assume that the functionalized imidazo[2,1-b]- [1,3]oxazines 5 apparently result from initial addition of the isocyanide to the acetylenic ester and subsequent protonation of the 1:1 adduct 6 by compound 4, followed by attack of the anion of the NH-acid 7 on the positively charged ion 8 to form ketenimine 9. Intermediate ketenimine 9 can isomerize under the reaction condition employed to produce the fused heterocyclic system 5.…”