title: Highly chemoselective calcium-catalyzed propargylic deoxygenation.
abstract: A calcium-catalyzed direct reduction of propargylic alcohols and ethers has been accomplished by using triethylsilane as a nucleophilic hydride source. At room temperature a variety of secondary propargylic alcohols was deoxygenated to the corresponding hydrocarbons in excellent yields. Furthermore, for the first time, a catalytic deoxygenation of tertiary propargylic alcohols was generally applicable. The same protocol was suitable for an efficient reduction of secondary as well as tertiary propargylic methyl, benzyl and allyl ethers. Substrates containing an additional keto-, ester or secondary hydroxyl function were reduced with exceptional chemoselectivity at the propargylic position.
authors.affiliation: Institute for Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
authors.forename: Vera J
authors.initials: VJ
authors.lastname: Meyer
authors.forename: Meike
authors.initials: M
authors.lastname: Niggemann
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry*; D002384:Catalysis; D004952:Esters; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010293:Pargyline / Q000737:chemistry*; D020005:Propanols / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000480:Alkynes; D004952:Esters; D020005:Propanols; D010293:Pargyline; C028255:propargyl alcohol; D002118:Calcium