John M. Brown' and Guy C. Lloyd-Jones ... Contribution from the Dyson Perrins Laboratory, South Parks Road, Oxford OX1 3QY, England Received February 9, 1993. Revised Manuscript Received November 18, 1993” ... Abstract: Attempted catalytic hydroboration of (4-methoxypheny1)ethene 1 with R,R-3-isopropyl-4-methyl-5-phenyl- 1,3,2-0xazaborolidine 6 proceeded extremely slowly relative to the 3-methyl analog 2 derived from cpephedrine when diphosphinerhodium ...