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A computational study of base‐catalyzed reactions between isocyanates and epoxides affording 2‐oxazolidones and isocyanurates
Author(s) -
Okumoto Satoshi,
Yamabe Shinichi
Publication year - 2001
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/1096-987x(200102)22:3<316::aid-jcc1004>3.0.co;2-5
Subject(s) - catalysis , base (topology) , chemistry , isocyanate , organic chemistry , mathematics , mathematical analysis , polyurethane
Title reactions were investigated with ab initio calculations. Methyl isocyanate and ethylene oxide were adopted as model reactants. The products, 2‐oxazolidones and isocyanurates, cannot be yielded without a base catalyst. The 2‐oxazolidone may be produced by a dual S N 2 reaction, where the catalyst base (e.g., Cl − ) is a nucleophile and a leaving group on the ethylene–oxide carbon. Isocyanurate is generated by the stepwise association of three isocyanate molecules, where one of the molecules is initially linked with a base. The six‐membered ring isocyanurate is isomerized stepwise into the components isocyanate and 2‐oxazolidone. A tetrahedral type of complex between the isocyanurate and a base‐catalyzed ethylene oxide is the key intermediate for the isomerization. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 316–326, 2001