Computational Studies of Organocatalytic Processes Based on Hydrogen Bonding

Computational Studies of Organocatalytic Processes Based on Hydrogen Bonding 

Hydrogen Bonding in Organic Synthesis. Edited by Petri M. Pihko Copyright 2009 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-31895-7 

Consequently, the processes most relevant to the topic of this chapter, that is, hydrogen bonds in organocatalytic transition states, are (i) transition state stabilization by pure hydrogen bonding (without full proton transfer), and (ii) general Bronsted-acid/Bronsted-based catalyzed reactions which are initiated by hydrogen bonding but move further to distinct proton transfer. 

In the majority of current theoretical pubhcahons deahng with organocatalysis, Becke s [8a, b] three parameter hybrid functional B3 and the Lee, Yang, and Parr (LYP) correlahon functional [8c] are used in combinahon with standard split valence basis sets (e.g., 6-3IG). In most cases, polarization functions that allow a greater flexibiHty of angle are added (for example, [d,p] means addihonal d-functions for second-row atoms, and additional p-funchons for hydrogen atoms) 

Transition states are clearly the most interesting stages of a reachon path. Nevertheless, we also consider starhng complexes and intermediates, provided that they contribute useful informahon about the mode of operahon of hydrogen bond mediated catalysis. 

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I 3 Computational Studies of Organocatalytic Processes Based on Hydrogen Bonding 3.1.1... 

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