Study On The Reaction Of Paraformaldehyde As C1 Source And Arylbenzyl Sulfone

The Knoevenagel condensation reaction is one of the simple and efficient common methods for constructing carbon-carbon double bonds using carbonyl compounds and active methylene compounds under weak base catalysis.Among them,carbonyl compounds are mainly concentrated in aromatic aldehydes,aromatic ketones and aliphatic aldehydes.Paraformaldehyde has the advantages of low toxicity,easy transportation and easy operation,so it often participates in the conversion reaction as an inexpensive C1 source in organic synthesis.This paper develops a class of Knoevenagel condensation reactions using arylbenzyl sulfone as the active methylene raw material,paraformaldehyde as the C1 carbon source,and further Michael addition reactions.1、Using arylbenzyl sulfone as raw material and paraformaldehyde as carbon source,a new method for efficiently synthesizing α-vinyl sulfone compounds without transition metals was developed.Substrates containing active hydroxyl and amino groups can be successfully used in this reaction system,and the double bonds of allylamine compounds can also be retained intact.The α-vinyl sulfone compounds and Michael addition compounds synthesized by this method have the advantages of mild conditions,simple conditions,and wide substrate applicability.2、Using arylbenzyl sulfone as raw material,paraformaldehyde as carbon source,methanol or dimethyl sulfoxide or secondary amine as nucleophilic reagent,a multicomponent efficient synthesis of β-alkoxy(nitrogen,sulfur)was developed Sulfone compound synthesis method.This reaction achieved the Knoevenagel condensation reaction and Michael addition reaction in a "one-pot".3、 In the absence of transition metals,triethylamine has been developed to promote the synthesis of(E)-vinyl sulfone compounds from arylbenzyl sulfone and paraformaldehyde.Through the study of the reaction mechanism,it was found that the reaction firstly produced Knoevenagel condensation reaction under the promotion of alkali to synthesize α-vinyl sulfone,and then synthesized(E)-vinyl sulfone compounds through intramolecular elimination reaction and intermolecular addition reaction.This method provides a new synthetic route for the synthesis of(E)-vinyl sulfone compounds.