A simple and efficient approach to the synthesis of highly functionalized fused benzochromenes

Synthesis of Coumarines and 4H-Chromenes through the Reaction oftert-Butyl Isocyanide and Dialkyl Acetylenedicarboxylates in Presence of 2-Hydroxybenzaldehydes

“…The presence of oxo and amino groups at one end of the double bond leads to polarization of the olefinic system. 12 The a-carbon atom of this polarized system appears at d = 162.13 ppm, while and the b-carbon at d = 72.04 ppm. The carbonyl groups of 8a appear at d = 169.67 and 172.99 ppm.…”

Synthesis of Ketenimines Derivatives from Reaction between Alkyl Isocyanides and Dialkyl Acetylenedicarboxylates in the Presence of Carboxylic Acid Arylidene-Hydrazides

“…There has been intense interest in their addition reactions, such as cycloaddition [3][4][5] Multicomponent reactions (MCRs), by virtue of their convergence, productivity, facile execution and generally high yields of products, have attracted much attention in the area of combinatorial chemistry [6][7][8] , of pivotal importance are the isocyanidebased MCRs 9 . The trapping of the 1:1 intermediate formed between dialkyl acetylenedicarboxylates and isocyanides with OH, NH and CH acids has been widely studied [10][11][12][13][14][15][16] . In continuation of our works on the reaction between isocyanides and dialkyl acetylenedicarboxylates in the presence of organic acids [17][18][19] , here we wish to report the results of our studies on the reaction between alkyl isocyanides and dialkyl acetylenedicarboxylates, in the presence of carboxylic acid arylidene-hydrazides.…”

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

“…There has been intense interest in their addition reactions, such as cycloaddition [13][14][15], nucleophilic [11,16,17], and electrophilic [18,19] addition. The trapping of the 1:1 intermediate formed between dialkyl acetylenedicarboxylates and isocyanides with OH, NH, and CH acids has been widely studied [20][21][22][23][24]. In continuation of our works on the reaction between isocyanides and acetylenic esters in the presence of organic acids [25][26][27][28], in this paper we present the results of an extended investigation on the reactivity of the intermediate zwitterion with 2,2,2-trifluoro-N-aryl-acetamides as N-H acids in dichloromethane leading to the formation of thermally stable ketenimine derivatives in good yields.…”