Synthesis carboxylates

M. Pomerantz, H. Yang, and Y. Cheng, Poly(alkyl thiophene-3-carboxylates). Synthesis and characterization of polythiophenes with a carbonyl group directly attached to the ring, Macromolecules, 28 5706-5708, 1995. 

Recent Applications of the Kolbe-Schmitt Carboxylation Synthesis of l,3-Dialkylimidazolium-2-Carboxylates... 

Stanovnik, B., Tisler, M. and Carlock, J.T. (1976) Heterocycles, CLIX. A novel synthesis of alkyl indole-3-carboxylates. Synthesis, (11), 754—755. 

This imidazoline-carboxylate synthesis involves the coupling of four separate cont5)onents (two imines, an acid chloride and carbon monoxide), and the generation of at least five separate bonds, all via a one-pot, palladium catalyzed process. From an analysis of the structure of the imidazoline carboxylate, the individual constituents can be seen (Figure 3). This stmcture might be considered to arise from the dipolar cycloaddition of an imine with a mesoionic l,3-oxazolium-5-oxide (5) intermediate, which itself could be generated from imine, acid chloride and carbon monoxide. Consistent with this potential formulation, performing the catalytic reaction with CO leads to the incorporation of the carbon-13 label into the carboxylate position of 4. 

A method similar to that used for phosphole carboxylate synthesis has been employed for the formation of ketones (279), (280), and (281) (Scheme 86) here the carbanion from a phosphole sulfide is reacted with ethyl acetate and the sulfur then removed with a phosphine <76T2395>. 

Dienes from 1,2,3-trienes via reductive carboxylation Synthesis of acetylene derivatives from 1,2,3-trienes Reductive alkylation... 

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