One-pot Synthesis Of Alkyne Ester Alkyne Nitrile Researches On The Methodology

Alkyne ester (R1C= C-COOR2) and alkyne nitrile (RC= C-CN) represent two classes of significant intermediates in the organic synthesis. With electron withdrawing groups directly attached to the carbon-carbon triple bonds, the acetylenic derivatives exhibited high reactive activities for various organic reactions. Thus a wide range of applications have been found in the fields of photoelectric materials, natural product materials, natural products and pharmaceutical molecules synthesis.One-pot preparation is an efficient and simple method to construct (C= C) triple bonds. Otera et al. have reported double-elimination towards substituted arynes. Based on the extensive literal investigations and long-standing research interests form our group, which has been successfully applied for the synthesis of arylethynyl sulfides, aryl diyne sulfides, bis(arylethynyl)sulfides and conjugated enyne sulfides, we herein wish to demonstrate a novel strategy for the preparations of alkyne esters and alkyne nitriles.In this thesis, we synthesized methyl-3-aryl-3-oxopropanoate firstly, using inexpensive and easily-prepared phenylethanone and dimethyl carbonate as raw materials for the subsequent one-pot reactions.Based on the explore on our laboratory, in this paper one pot synthesis of alkyne ester conditions were some changes, particularly in operation of the present experiment is as follows:under nitrogen and-78℃ conditions firstly LiHMDS (1.2 eq) was added to the methyl-3-aryl-3-oxopropanoate in THF reaction 30 min:then added C1P(O)(OEt)2 (1.5 eq) under conditions reaction at room temperature 1.5 h; then at-78℃ conditions added LiHMDS (2.0 eq) reaction 1 h. The reaction was quenched with aqueous NH4CI solution and the crude products was subsjected to flash column chromatography (petroleum ether as eluent)to give alkyne ester.On the synthesis of alkyne nitrile, Available aryl formaldehyde as a starting material reacted with acetonitrile obtained in 3-aryl-2-propynenitriles. Then available 3-oxo-3-phenylpropionitrile as substrates one-pot synthesis alkyne nitrile. Synthesis of alkyne nitrile conditions also had some changes. Based on ester alkyne synthesis after a series of experiments to explore the optimal conditions. We get good results at a temperature of-60℃ condition one pot synthesis of alkyne nitrile.This method has good features in short synthetic route, green, high yield and inexpensive raw material which is a effective way to synthesize rare acetylide. The method is applicable to all types of non-proton on the benzene substituents (such as methyl, methoxy, halogen, etc.), while the paper also successfully synthesized alkyne ester having a heterocyclic ring, All the evidence demonstrated that one-pot synthesis method has broad applicability.All of the compounds herein, and some are never reported a substrate by 1H NMR,13C NMR, HRMS, MS, was confirmed.