Paper Info
Title
Mechanistic insights on DBU catalyzed β-amination of nbs to chalcone driving by water: Multiple roles of water.
Abstract
DFT calculations were conducted to pursue deeper understandings on the mechanism and the explicit role of trace water in the DBU-catalyzed beta-amination of NBS to chalcone. Being different from previously proposed by Liang et al., a cooperative participation of both DBU and water is noticed in the preferred mechanism. The preferential mechanistic scenario assisted by water undergoes three major steps: the formation of succinimide and HBrO, concerted nucleophilic addition and H-shift, and keto-enol tautomerization. Moreover, we found that DBU-HBrO is unnecessary in the third step and three-water-cluster assisted keto-enol tautomerization is the most advantageous case. It is further noted that the catalytic position of the third water molecule and the proton shift orientation to some extent affect step 3 via O center dot center dot center dot H-O and O-H center dot center dot center dot pi interactions, which is confirmed by AIM analysis. The computational results suggest that water molecules play pivotal roles as reactant, catalyst, and stabilizer to promote the reaction of chalcone and NBS. The origin of the more stable transition state structure in the rate-determining step of DBU-water catalyzed mechanism is ascribed to noncovalent interactions, halogen bond, and electrostatic interactions than DBU only ones. (C) 2017 Wiley Periodicals, Inc.
Year
DOI
Venue
2017
10.1002/jcc.24700
JOURNAL OF COMPUTATIONAL CHEMISTRY
Keywords
Field
DocType
DBU,water,density functional theory,mechanism,beta-amination of chalcone
Catalysis,Organic chemistry,Amination,Computational chemistry,Chemistry,Density functional theory,Mechanism (philosophy),Chalcone
Journal
Volume
Issue
ISSN
38.0
7
0192-8651
Citations 
PageRank 
References 
0
0.34
3
Authors
2
Name
Order
Citations
PageRank
Haiyan Yuan101.69
Jingping Zhang297.30