(S)-4-Isopropyl-5,5-diphenyloxazolidin-2-one

Abstract

(S)-4-Isopropyl-5,5-diphenyloxazolidin-2-one has been synthesized for the first time by the enantiospecific oxidative carbonylation of commercially available (S)-2-amino-3-methyl-1,1-diphenylbutan-1-ol. The cyclocarbonylation reaction was carried out at 100 °C in 1,2-dimethoxyethane (DME) as the solvent for 15 h, under 20 atm of a 4:1 mixture of CO–air and in the presence of the catalytic system PdI2/KI (substrate:KI:PdI2 molar ratio = 100:10:1), to give the oxazolidinone derivative in 81% isolated yield.

PdI2-Based Catalysis for Carbonylation Reactions: A Personal Account

“…The isocyanate intermediate deriving from a primary amine under PdI2-catalyzed oxidative carbonylation conditions can also be trapped intramolecularly by a second nucleophilic group. Thus, cyclic ureas [87], 2-oxazolidinones [90][91][92][93], and benzoxazolones [90,92] were obtained in excellent yields from aromatic diamines, β-amino alcohols, and 2-aminophenols, respectively, as exemplified in Scheme 27. More recently, we found that it is also possible to carry out this transformation in the ionic liquid (IL) BmimBF 4 (1-butyl-3-methylimidazolium tetrafluoroborate) as an unconventional solvent, with the possibility to recycle the catalyst-IL system (Scheme 26) [90].…”