Applications of Selenonium Cations as Lewis Acids in Organocatalytic Reactions

2018 ◽  
Vol 130 (39) ◽  
pp. 13051-13055 ◽  
Author(s):  
Xinxin He ◽  
Xinyan Wang ◽  
Ying-Lung Steve Tse ◽  
Zhihai Ke ◽  
Ying-Yeung Yeung
Keyword(s):  
Lewis Acids ◽  
Organocatalytic Reactions

scholarly journals Application of Halogen Bonding to Organocatalysis: A Theoretical Perspective

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1045 ◽  
Author(s):  
Hui Yang ◽  
Ming Wah Wong
Keyword(s):  
Crystal Engineering ◽  
Lewis Acids ◽  
Halogen Bond ◽  
Theoretical Perspective ◽  
Halogen Bonding ◽  
Catalyst Design ◽  
Methodology Development ◽  
Wide Range ◽  
Promising Area ◽  
Organocatalytic Reactions

The strong, specific, and directional halogen bond (XB) is an ideal supramolecular synthon in crystal engineering, as well as rational catalyst and drug design. These attributes attracted strong growing interest in halogen bonding in the past decade and led to a wide range of applications in materials, biological, and catalysis applications. Recently, various research groups exploited the XB mode of activation in designing halogen-based Lewis acids in effecting organic transformation, and there is continual growth in this promising area. In addition to the rapid advancements in methodology development, computational investigations are well suited for mechanistic understanding, rational XB catalyst design, and the study of intermediates that are unstable when observed experimentally. In this review, we highlight recent computational studies of XB organocatalytic reactions, which provide valuable insights into the XB mode of activation, competing reaction pathways, effects of solvent and counterions, and design of novel XB catalysts.

Applications of Selenonium Cations as Lewis Acids in Organocatalytic Reactions

2018 ◽  
Vol 57 (39) ◽  
pp. 12869-12873 ◽  
Author(s):  
Xinxin He ◽  
Xinyan Wang ◽  
Ying-Lung Steve Tse ◽  
Zhihai Ke ◽  
Ying-Yeung Yeung
Keyword(s):  
Lewis Acids ◽  
Organocatalytic Reactions

Enantioselective Organocatalytic Reactions with Isatin

2013 ◽  
Vol 17 (18) ◽  
pp. 1957-1985 ◽  
Author(s):  
MariFe Flores ◽  
Javier Pena ◽  
Pilar García-García ◽  
Narciso Garrido ◽  
David Diez
Keyword(s):  
Organocatalytic Reactions

Organocatalyzed Heterocyclic Transformations In Green Media: A Review

2020 ◽  
Vol 07 ◽  
Author(s):  
Neslihan Demirbas ◽  
Ahmet Demirbas
Keyword(s):  
Hydrogen Bonding ◽  
Phase Transfer ◽  
Noncovalent Interactions ◽  
Binding Capacity ◽  
Chemical Transformations ◽  
Organic Transformations ◽  
Phase Transfer Catalysts ◽  
Waste Production ◽  
Synthetic Methodologies ◽  
Organocatalytic Reactions

Background: Since the discovery of metal-free catalysts or organocatalysts about twenty years ago, a number of small molecules with different structures have been using to accelerate organic transformations. With the development of environmental awareness, in order to obtain highly privileged scaffolds, scientists have directed their studies towards the synthetic methodologies which minimize or preferably eliminate the formation of waste, avoid from toxic solvents and reagents and use renewable starting materials as far as possible. Methods: In this connection, the organocatalytic reactions providing efficiency and selectivity for most of case have become an endless topic in organic chemistry since several advantages from both practical and environmental standpoints. Organocatalysts supplying transformation of reactants into products with the least possible waste production have been serving to the concept of green chemistry. Results and Conclusion: Organocatalysts have been classified on the basis of their binding capacity to the substrate with covalently or noncovalent interactions involving hydrogen bonding and electrostatic interaction. Diverse types of small organic compounds including proline and its derivatives, phase-transfer catalysts, (thio)urease, phosphoric acids, sulfones, N-oxides, guanidines, cinchona derivatives, aminoindanol and amino acids have been utilized as hydrogen bonding organocatalysts in different chemical transformations.

scholarly journals Theoretical Insight into the Reversal of Chemoselectivity in Diels-Alder Reactions of α,β-Unsaturated Aldehydes and Ketones Catalyzed by Brønsted and Lewis Acids

Organics ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 38-49
Author(s):  
Lakhdar Benhamed ◽  
Sidi Mohamed Mekelleche ◽  
Wafaa Benchouk
Keyword(s):  
Lewis Acids ◽  
Major Product ◽  
Diels Alder ◽  
Unsaturated Ketone ◽  
Unsaturated Aldehydes ◽  
Aldehydes And Ketones ◽  
Theoretical Insight ◽  
Insight Into ◽  
Good Agreement

Experimentally, a reversal of chemoselectivity has been observed in catalyzed Diels–Alder reactions of α,β-unsaturated aldehydes (e.g., (2E)-but-2-enal) and ketones (e.g., 2-hexen-4-one) with cyclopentadiene. Indeed, using the triflimidic Brønsted acid Tf2NH as catalyst, the reaction gave a Diels–Alder adduct derived from α,β-unsaturated ketone as a major product. On the other hand, the use of tris(pentafluorophenyl)borane B(C6F5)3 bulky Lewis acid as catalyst gave mainly the cycloadduct of α,β-unsaturated aldehyde as a major product. Our aim in the present work is to put in evidence the role of the catalyst in the reversal of the chemoselectivity of the catalyzed Diels–Alder reactions of (2E)-but-2-enal and 2-Hexen-4-one with cyclopentadiene. The calculations were performed at the ωB97XD/6-311G(d,p) level of theory and the solvent effects of dichloromethane were taken into account using the PCM solvation model. The obtained results are in good agreement with experimental outcomes.

scholarly journals Understanding How Lewis Acids Dope Organic Semiconductors: A “Complex” Story

2021 ◽  
Author(s):  
Pablo Simon Marques ◽  
Giacomo Londi ◽  
Brett Yurash ◽  
Thuc-Quyen Nguyen ◽  
Stephen Barlow ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Lewis Acids ◽  
Computational Studies

We report on computational studies of the potential of three borane Lewis acids (LAs) (B(C6F5)3 (BCF), BF3, and BBr3) to form stable adducts and/or to generate positive polarons with three...

scholarly journals Bulky Polyfluorinated Terphenyldiphenylboranes. Water Tolerant Lewis Acids

2020 ◽  
Author(s):  
Corina Stoian ◽  
Marian Olaru ◽  
Theodor Cucuiet ◽  
Krisztina Kegyes ◽  
Alexandru Sava ◽  
...  
Keyword(s):  
Lewis Acids
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