Reactions of organic anions. XXVI. Catalytic alkylation of ketones in aqueous medium

Computational Studies on the Diastereospecific Lithium Variant of Oppenauer Oxidation of a Tofisopam Intermediate

“…In conclusion, the Gibbs free energies and the geometric observations of the reaction of lithium complexes (S,R)-13 and (R,R)-13 with 3,4-dimethoxybenzaldehyde (8) suggest that the lithium-catalyzed-Oppenauer oxidation leading to ketone 12 is more advantageous for diastereomeric racemate (RS,SR)-13A than for (RR,SS)-13B (Scheme 4), supporting the observation that only alcohol 14B is formed in the reaction in addition to ketone 12. From this result, it also follows that the absolute configuration of product 14B can be assigned: it is RR,SS.…”

“…Ethylation at the benzylic carbon atom followed by reduction of the carbonyl group gave a mixture of stereoisomeric alcohols 7 . Treatment of 7 with 3,4-dimethoxybenzaldehyde ( 8 ) afforded isochroman isomers 9 , which were oxidized to diketone 2 with chromium­(VI) oxide. − …”

Phase-Transfer Catalysis Reaction with Strong Bases

“…As the steric hinderance of the alkyl iodide increases (Mel < Etl < n-BuI < iso-Propl), the percent C-alkylation of tetrabutylammonium + [a-benzoyldimethylmalonate]-, 4, decreases from 100% to 14%. 5, the percent C-IO-alkylation ratio decreases from 13.8 to 0.72. Guidelines for selectivity of alkylation of ambident anion.…”

“…zylammonium chloride and no solvent [5]. The pKa of phenylacetone is likely to be approximately 15-18 [6], and the reaction is likely to be hydroxide transfer rate limited.…”

Reações de sulfenilação de compostos α-sulfonil carboxílicos

“…Em 1971, Jonczyk e col. 96,97 descreveram a alquilação da fenilacetona utilizando o método de Makosza, ou seja, NaOH aquoso e concentrado e Tebac em quantidade catalítica. Na maioria dos casos, somente a monoalquilação foi observada.…”