The multieffects of DMF and DBU on the [5 + 1] benzannulation of nitroethane and α‐alkenoyl ketene‐(<i>S,S</i>)‐acetals: Hydrogen bonding and electrostatic interactions

Yuan, Haiyan; Zheng, Yiying; Li, Bo; Li, Wenliang; Zhang, Jingping

doi:10.1002/jcc.23846

Cited by 6 publications

(3 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our previous works indicate that solvent media play an important role in facilitating the proton transfer and effectively lowering the energy barrier . The solvent used in the experiment is water.…”

Section: Resultsmentioning

confidence: 99%

Mechanistic insight on (E)‐methyl 3‐(2‐aminophenyl)acrylate cyclization reaction by multicatalysis of solvent and substrate

et al. 2016

Self Cite

View full text Add to dashboard Cite

The reaction mechanism of (E)-methyl 3-(2-aminophenyl)acrylate (A) with phenylisothiocyanate (B) as well as the vital roles of substrate A and solvent water were investigated under unassisted, water-assisted, substrate A-assisted, and water-A-assisted conditions. The reaction proceeds with four processes via nucleophilic addition, deprotonation and protonation, intramolecular cyclization with hydrogen transfer, and keto-enol tautomerization. According to the different H-shift mode, two possible types of H-shift P1 and P2 are carefully investigated to identify the most preferred pathway, differing in the NH2 group deprotonation and CH group of A protonation processes. It is found that substrate A and water not only act as reactant and solvent, but also as catalyst, proton shuttle, and stabilizer in effectively lowering the energy barrier. Therefore, the results demonstrate that the strong donating and accepting ability of NH2 group on A and the presence of bulk water are the keys to the title reaction proceed. © 2016 Wiley Periodicals, Inc.

show abstract

Section: Resultsmentioning

confidence: 99%

Mechanistic insight on (E)‐methyl 3‐(2‐aminophenyl)acrylate cyclization reaction by multicatalysis of solvent and substrate

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…It was proposed that the nucleophilic addition of DBU could also be applied as a Lewis base to mediate benzannulation reaction. [33] For instance, the DBU-mediated one-pot tandem reaction of 3-(1alkynyl)chromones 55 and acetonitriles 56 under microwave irradiation via a tandem Michael addition/ cyclization/1,2-addition process, produced the functionalized amino-substituted xanthones 57 in high yields. [34] This method provided an efficient approach to establish natural product-like diversified polysubstituted amino-xanthone scaffolds rapidly (Scheme 11a).…”

Section: Tertiary Amine-mediated Benzannulation Reactionsmentioning

confidence: 99%

Recent Advances in Organocatalyst‐Mediated Benzannulation Reactions

2020

Adv Synth Catal

View full text Add to dashboard Cite

Aromatic compounds are omnipresent in organic chemistry, which are the broadest skeletons of bioactive molecules, medicines, and materials. Due to their importance, conventional methods to assemble aromatic rings have attracted considerable attention. The direct formation of benzene cores from readily available acyclic precursors offers a highly versatile and superior approach to prepare both small organic molecules and sophisticated natural products. Recently, organocatalyst-mediated annulation reaction, including phosphine-, tertiary amine-, secondary amine-, primary amine-, and NHC-mediated benzannulation reactions, is considered as an efficient method to access multi-substituted arenes. In this review, we will emphasize the selected examples of organocatalyst-mediated benzannulation reactions of available acyclic precursors for the construction of diverse aromatics.

show abstract

“…We envisage that there is another possibly combinational mode for DBU and NBS. As a part of our continued efforts in understanding mechanistic insights into DBU‐catalyzed reactions, we investigated the DBU/NBS‐catalyzed β ‐amination of chalcones reaction by using density functional theory computational method. We aimed to disclose (1) the effect of water on the interaction of DBU and NBS, (2) the difference of DBU‐catalyzed mechanisms with or without water, (3) the actual role of water as well as the active catalytic site in this reaction, (4) the origin of the differential in DBU and DBU‐water catalyzed mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Mechanistic insights on DBU catalyzed β‐amination of nbs to chalcone driving by water: Multiple roles of water

Yuan

Zhang

2017

J Comput Chem

Self Cite

View full text Add to dashboard Cite

DFT calculations were conducted to pursue deeper understandings on the mechanism and the explicit role of trace water in the DBU-catalyzed β-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···HO and OH···π 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. © 2017 Wiley Periodicals, Inc.

show abstract

The multieffects of DMF and DBU on the [5 + 1] benzannulation of nitroethane and α‐alkenoyl ketene‐(S,S)‐acetals: Hydrogen bonding and electrostatic interactions

Cited by 6 publications

References 58 publications

Mechanistic insight on (E)‐methyl 3‐(2‐aminophenyl)acrylate cyclization reaction by multicatalysis of solvent and substrate

Mechanistic insight on (E)‐methyl 3‐(2‐aminophenyl)acrylate cyclization reaction by multicatalysis of solvent and substrate

Recent Advances in Organocatalyst‐Mediated Benzannulation Reactions

Mechanistic insights on DBU catalyzed β‐amination of nbs to chalcone driving by water: Multiple roles of water

Contact Info

Product

Resources

About