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The phase-transfer methylation of 6,7-dichloro-5-methoxy-2-phenyl-l-indanone by MeCl in 50% NaOH/toluene using substituted N-benzylcinchoninium halides has provided the methylated indanone 2 in ee's up to 94%. The effects of solvent, alkylating agent, temperature, and catalyst were investigated: nonpolar solvents gave higher ee's than polar solvents; MeCl gave a higher ee than did MeBr and Mel; and temperature had little effect on the reaction. A Hammett plot of log ee/ee0 vs. a for the N-benzylcinchoninium halide catalysts gave a reaction constant p of 0.21 with an ee range of 60% to 94%, demonstrating that substituents with increasing electronwithdrawing power improve catalyst selectivity. A kinetic and mechanistic study of the reaction has revealed several unusual features. In 50% NaOH/toluene these include the following: (1) the indanone 1 is deprotonated at the interface to form the sodium enolate as a separate solid phase; (2) the substituted IV-benzylcinchoninium catalysts are extracted into the organic layer as dimers; and (3) the kinetic order in MeCl is 0.7 and in catalyst is 0.55. In 30% NaOH/toluene the following obtain: (1) no solid enolate is formed; (2) an order in catalyst of 0.5 was found for the chiral methylation pathway, while an order of 1.0 was found for the racemic methylation pathway.

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[structure: see text]. In the stoichiometric asymmetric epoxidation of E-beta-methylstyrene with cationic chromium-salen oxo complexes, enantioselectivity is increased by halo-substitution at the 3,3'- and 6,6'-positions and decreased at the 4,4'- and 5,5'-positions on the salen rings. Addition of triphenylphosphine oxide significantly increases selection with 3,3'- or 5,5'-substituents but not with 4,4'- or 6,6'-substituents. Use of nitrate counterion is beneficial in most cases. The results are discussed with respect to the mode of stereoselection in metal-salen epoxidations.