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Structure–Reactivity Relationship Studies for Guanidine‐Organocatalyzed Direct Intramolecular Aldolization of Ketoaldehydes
Author(s) -
Ghobril Cynthia,
Hammar Peter,
Kodepelly Sanjeevarao,
Spiess Bernard,
Wagner Alain,
Himo Fahmi,
Baati Rachid
Publication year - 2010
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201000227
Subject(s) - guanidine , reactivity (psychology) , intramolecular force , chemistry , catalysis , density functional theory , computational chemistry , transition state , aldol reaction , combinatorial chemistry , stereochemistry , organic chemistry , alternative medicine , medicine , pathology
Structure–reactivity studies are performed to explore the reaction mechanism of the guanidine‐catalyzed intramolecular aldol reaction of ketoaldehydes. A large number of guanidine and guanidine‐like catalysts are synthesized and their properties studied. Kinetic profiles and p K a values of the catalysts are measured and correlated to reaction barriers calculated using density functional theory (DFT). The DFT calculations show that structural rigidity influences the p K a of the guanidines. Although the basicity is a very important factor in the catalysis, it is not sufficient to fully account for its catalytic efficiency. The availability of two aligned nitrogen reaction sites for proton shuttling in the transition state is an essential feature that helps to rationalize the reactivity pattern and the activation mode for this family of organocatalysts.