A hierarchy of aryloxide deprotection by boron tribromide.
Aryl propargyl ethers and esters are cleaved selectively in the presence of aryl methyl ethers and esters by boron tribromide in dichloromethane. Under the same conditions, allyl ethers undergo very rapid Claisen rearrangement, and benzyl ethers are also cleaved more rapidly than propargyl. A mechanism involving intramolecular delivery of bromide to the propargyl terminus is proposed. [reaction: see text]
Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Sreenivas
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Punna
Stéphane
S
Meunier
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MG
Finn
D000498:Allyl Compounds / Q000737:chemistry; D001593:Benzyl Compounds / Q000737:chemistry; D001896:Boron Compounds / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry*; D010087:Oxides
D000498:Allyl Compounds; D001593:Benzyl Compounds; D001896:Boron Compounds; D001965:Bromides; D004952:Esters; D004987:Ethers; D010087:Oxides