On the condensation of 2,2-difluoro-4-methyl-benzo[d]-1,3,2-dioxaborines with cyano acetic acid derivatives. Formation and transformation of 3-cyano-4-methyl-benzo[b]pyran-2-ones and their 2-imine precursors
摘要:
By condensation of 2,2-difluoro-4-methyl-benzo[d]-1,3,2-2H-dioxaborines (12) with cyano acetic acid derivatives in presence of weak bases, 3-cyano-4-methyl-benzo[b]pyran-2-ones (13) or their 3-cyano-4-methyl-benzo[b]pyran-2-imine precursors (14) are available in satisfactory yields.
An efficient one-potsynthesis of coumarins mediated by T3P, a mild and low toxic peptide coupling agent, via the Perkin condensation has been demonstrated.
Condensation of some ketones with methylene active nitriles in varied stoichiometries
作者:Emmanuel Sopbué Fondjo、Dietrich Döpp
DOI:10.1002/jhet.5570430433
日期:2006.7
Condensations of some ketones, such as cyclopentanone, cyclohexanone, indan-1,3-dione, 2-acetyl-1-naphthol, 1-acetyl-2-naphthol, with someactivemethylenecompounds, such as malononitrile and cyanoacetate, in the presence of amine bases, diethylamine or triethylamine, were studied. The structures of the Knoevenagel condensation products were determined by spectral analyses.
Vinylogous Nucleophiles Bearing the Endocyclic Double Bond in the Allylic Alkylation with Morita-Baylis-Hillman Carbonates
作者:Dorota Kowalczyk、Łukasz Albrecht
DOI:10.1002/adsc.201701185
日期:2018.2.1
nucleophilicity in the allylic alkylation with Morita‐Baylis‐Hillman carbonates can be accomplished through the endocyclic double bond in 3‐cyano‐4‐methylcoumarins. The developed reaction provides a straightforward access to functionalized coumarin derivatives of biological and synthetic relevance. Target, highly functionalized products have been chemoselectively and efficiently obtained in very high yield