Tandem Michael addition–Claisen-type condensation of anions of <i>O</i>-ethyl carbonates of cyanohydrins to cyclohex-2-en-1-one
作者:Héctor M. Torres Domínguez、Luis A. Maldonado、Ronan Le Lagadec
DOI:10.1080/00397911.2017.1322106
日期:2017.7.3
2-acetoxy-6-aroylcyclohex-1-ene-1-carboxylates and ethyl 2-acetoxy-6-heterocarbonylcyclohex-1-ene-1-carboxylates through Michael addition of the anions of ethyl carbonates of cyanohydrins to cyclohex-2-en-1-one and subsequent reaction with acetic anhydride is described. These compounds are potential intermediates for the synthesis of 9,10-anthraquinone and heterofused 1,4-naphthoquinone derivatives
Efficient synthesis in water of mixed carbonates of cyanohydrins from aromatic aldehydes
作者:Torres Domínguez Héctor Manuel、Maldonado Luis Ángel、Le Lagadec Ronan
DOI:10.1016/j.tetlet.2019.151414
日期:2020.1
An efficient preparation of cyanohydrin ethyl carbonates via cyanocarbonation of aromatic and hetero-aromatic aldehydes with sodium cyanide and ethyl chlorocarbonate using commercial surfactants (5 mol %) in aqueous media at low temperature afforded almost quantitative isolated yields (≥ 94 %) in 30 minutes. Aromaticaldehydes bearing electron-donating as well as electron-withdrawing groups have been
A facile synthesis of aryl α-keto esters is reported involving the rearrangement of aryl cyanohydrin carbonate esters induced by the α-carbanion to the nitrile group generated by LDA. However, under similar conditions, an o-benzyloxycyanohydrin carbonate esterrearrangedvia a domino reaction leading to 2-phenylbenzofuran-3-carboxylic acid.
N-heterocyclic carbene catalyzed cyanation reaction of carbonyl compounds with ethyl cyanoformate and acetyl cyanide
作者:Jie Zhang、GuangFen Du、YueKe Xu、Lin He、Bin Dai
DOI:10.1016/j.tetlet.2011.10.119
日期:2011.12
employed as an efficientcatalyst for cyanation reaction of carbonyl compounds. Under catalysis of 1 mol % NHCs, various aldehydes and 2,2,2-trifluoroacetophenone coupled with ethyl cyanoformate in THF to provide cyanohydrins ethyl carbonates in excellent yields. While in the presence of 10 mol % catalyst, different types of aldehydes and 2,2,2-trifluoroacetophenone reacted with acetyl cyanide in dichloroethane
higher catalytic activity than that modified by hydrophilic ethanolamine groups. PANBTF can efficiently and rapidly catalyze the cyanation reaction of benzaldehyde and ethyl cyanoformate in water with a yield of 94 % at room temperature within 40 min. Moreover, a mechanism promoted by the hydrophobic microenvironment has been proposed to explain the high and specific catalytic activity of PANBTF. In addition