These borane syntheses and the related nitrile syntheses are old and well known to many. Some other related refs are JACS 90: 5280,5936 & 6891 (1968) & 91: 4304, 6852 & 6854 Diazoeacetone can be used as an alternative to bromoacetone. They work very well with the substituted aromatics. While not the cheapest, these routes offer the advantage of being generally applicable, and thus very suited for our purposes.