Dual Activity of Grubbs-Type Catalyst in the Transvinylation of Carboxylic Acids and Ring-Closing Metathesis Reactions

Abstract

The development of a multifunctional catalyst, which mimics the promiscuity of enzymes, that would catalyze more than one chemical transformation in a single reaction vessel is one of the key points of modern sustainable chemistry. The results of our experiments indicated that Grubbs-type catalysts possess such multitask activity, catalyzing the transvinylation reaction of carboxylic acids without losing their original metathetic activity. This new activity of Grubbs catalysts was evidenced on several examples. It allows us to design a transvinylation/ring-closing metathesis (RCM) cascade reaction leading to the formation of endocyclic enol lactones from unsaturated carboxylic acids in an one-pot procedure. This unique ability of Grubbs catalyst to catalyze multiple mechanically distinct cascade reactions in a chemoselective way offers the new possibility for the synthesis of complex compounds from simple, easily accessible substrates.

Evaluation of gem-Diacetates as Alternative Reagents for Enzymatic Regio- and Stereoselective Acylation of Alcohols

“…Recently, we have shown that gem -acetates (1,1-diacetates), which are carbonyl surrogates, can be effectively deprotected by hydrolases under aqueous conditions to the parent aldehydes . As part of our ongoing research on environmentally sustainable protocols, we devoted our attention to develop protocols toward acetates, which combines both economic and green chemistry aspects. As a result of our intensive work on the development of an effective method for the synthesis of carboxylic acid esters, , we wish to report geminal diacetates as sustainable reagents for the enzyme-catalyzed acylation of various primary and secondary alcohols.…”

Model Studies on the Enzyme‐Regulated Stereodivergent Cascade Passerini Reaction

“…To overcome the principal limitation to design an elegant cascade with compatible conditions for all steps, we have applied various vinyl ester 9 – 12 and an isocyanide into a one‐pot reaction. As model reactants, we applied vinyl 2‐methylhydrocinnamate [13] ( 9 ) and p ‐methoxybenzylyisocyanide in a phosphate buffer pH 7.4. We started our investigation with the reaction in the absence of an enzyme, wherein neither the formation of product 15 nor its subsequent hydrolysis product were observed (Table 1, entry 1).…”

“…In the first step, the enzyme performs a kinetic resolution of the racemic vinyl ester (9-12) leading to the formation of enantioenriched carboxylic acid (14) and acetaldehyde (13). Next, generated compounds follow the Passerini condensation with an isocyanide, present in the reaction mixture.…”