Synthesis Of Enol Research Articles

Synthesis of Enol and Vinyl Esters Catalyzed by an Iridium Complex.

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Synthesis of enol and vinyl esters catalyzed by an iridium complex

Enol and vinyl esters were successfully synthesized by the use of an iridium complex as a catalyst. The reaction of carboxylic acids with terminal alkynes in the presence of catalytic amounts of [Ir(cod)Cl] 2 and Na 2CO 3 gave the corresponding 1-alkenyl esters. The addition of carboxylic acids to alkynes principally took place in the Markovnikov fashion. In addition, by the use of an Ir complex combined with NaOAc various vinyl esters were prepared through the transvinylation between carboxylic acids and vinyl acetate.

Betylates. 1. Synthesis and reactions of an isolable [0]betylate, N,N-dimethyl-N-(phenoxysulfonyl)methanaminium fluorosulfate

Phenyl [0]betylate fluorosulfate (2), the first example of a "[0]betylate" (trialkylammoniosulfate ester), has been prepared by methylation of phenyl N,N-dimethylsulfamate with methyl fluorosulfate. Nucleophiles react with 2 either by attack on the sulfur or methyl carbon atoms, but with no sign of any products derived from benzyne or the phenyl cation. A synthesis of enol N,N-dimethylsulfamates has been devised using a reagent, [Formula: see text], prepared from tetramethylsulfamide and methyl fluorosulfate, but no satisfactory method was found for converting the sulfamic ester to the [0]betylate. Evidence is presented that phenyl chlorosulfate reacts with trimethylamine to give the phenyl [0]betylate which then undergoes further reaction.