Kinetic profiling has shown that a (DHQD) 2 PHALcatalyzed intermolecular asymmetric alkene bromoesterification reaction is inhibited by primary amides, imides, hydantoins, and secondary cyclic amides, which are byproducts of common stoichiometric bromenium ion sources. Two approaches to resolving the inhibition are presented, enabling the (DHQD) 2 PHAL loading to be dropped from 10 to 1 mol % while maintaining high bromoester conversions in 8 h or less. Iterative post-reaction recrystallizations enabled a homochiral bromonaphthoate ester to be synthesized using only 1 mol % (DHQD) 2 PHAL.

This communication describes an unprecedented substitution cascade, in which 4-methylpyridine, following deprotonation with LDA, twice acts as a carbon nucleophile in an unusual SNAr process, to form a novel triarylmethane structure. A proposed mechanism for this sequence is presented that is supported by single crystal X-ray analysis of the resulting product. We believe this unique transformation is of note as it highlights a neat and efficient entry as a single step to complex triarylmethane architectures containing both substituted phenyl and pyridyl aromatics.