Halogenation, a-Alkylation, and Related Reactions

Key advances in a-fluorination which occurred in 2005, using both organo- and metallo-catalytic approaches, have been reviewed (21 references).295 

A mild metal-free a-iodi nation of ketones uses molecular iodine in a neutral reaction medium.296 Aliphatic ketones react predominantly on the more substituted side, with 

A new synthesis of pyrroles generates a 1,3-diketone by reacting a lithium enolate of a ketone with an acid chloride in situ addition of a hydrazine yields, potentially, a tetrasubstituted pyrazole.297 Tolerant of a wide range of functional groups, it is also easily adapted to rapid preparation of fused bicyclic pyrazole systems. 

The utility of global and local reactivity descriptors to predict chemical reactivity and C- versus O-alkylation has been investigated for the case of lithium enolates.298 

The origin of the dramatically increased enantioselectivity of a-alkylation of aldehydes when 2-methylproline is substituted for proline as organocatalyst has been investigated using DFT.299 

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