On the relative migratory aptitudes of carbon and heteroatoms in borate complexes. A surprising α-thia effect

JM Stoddard, KJ Shea

Index: Stoddard, Jonathan M.; Shea, Kenneth J. Chemical Communications, 2004 , # 7 p. 830 - 831

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Citation Number: 6

Abstract

Recently, trialkylboranes have been found to react with dimethylsulfoxonium methylide (1) 13 resulting in multiple insertions of methylene into the carbon–boron bond. Attempts at using oxygen ligands as blocking groups for homologation of alkyl boronic esters with ylide 1 were unsuccessful. For example, phenyl catechol boronate ester (2) was reacted with 1 equiv. of ylide 1 in toluene at 23 °C (Scheme 1) to form a borate complex ( 11 B NMR 9.6 ppm, toluene). ...