Bromonium salts: diaryl-λ3-bromanes as halogen-bonding organocatalysts

2021 ◽  
Author(s):  
Yasushi Yoshida ◽  
Seitaro Ishikawa ◽  
Takashi Mino ◽  
Masami Sakamoto
Keyword(s):  
Halogen Bonding ◽  
Product Yield ◽  
Catalytic Application ◽  
Leaving Groups

Bromonium salts have been typically but infrequently used as good leaving groups owing to their high nucleofugality. Herein, we report the synthesis of stable bromonium salts and their first catalytic application, with excellent product yield.

The X40x10 Halogen Bonding Benchmark Revisited: Surprising Importance of (n-1)d Subvalence Correlation

2017 ◽  
Author(s):  
Manoj Kumar Kesharwani ◽  
Nitai Sylvetsky ◽  
Debashree Manna ◽  
Jan M.L. Martin
Keyword(s):  
Dissociation Energy ◽  
Noncovalent Interactions ◽  
Halogen Bonding ◽  
Coupled Cluster ◽  
Dissociation Energies ◽  
Iodine Species ◽  
Explicitly Correlated ◽  
High Level ◽  
Cluster Methods ◽  
Small Separation

<p>We have re-evaluated the X40x10 benchmark for halogen bonding using conventional and explicitly correlated coupled cluster methods. For the aromatic dimers at small separation, improved CCSD(T)–MP2 “high-level corrections” (HLCs) cause substantial reductions in the dissociation energy. For the bromine and iodine species, (n-1)d subvalence correlation increases dissociation energies, and turns out to be more important for noncovalent interactions than is generally realized. As in previous studies, we find that the most efficient way to obtain HLCs is to combine (T) from conventional CCSD(T) calculations with explicitly correlated CCSD-F12–MP2-F12 differences.</p>

Catalytic Application of Mesoporous ZSM-5 Zeolite

2014 ◽  
Vol 18 (10) ◽  
pp. 1305-1322 ◽  
Author(s):  
Zheng Wu ◽  
Yi Wang
Keyword(s):  
Catalytic Application

Zinc Sulfamate Catalyzed Efficient Selective Synthesis of Benzimidazole Derivatives under Ambient Conditions

2019 ◽  
Vol 16 (9) ◽  
pp. 740-749
Author(s):  
Sushil R. Mathapati ◽  
Arvind H. Jadhav ◽  
Mantosh B. Swami ◽  
Jairaj K. Dawle
Keyword(s):  
Benzimidazole Derivative ◽  
Sulfamic Acid ◽  
Aromatic Aldehydes ◽  
Catalytic Amount ◽  
Product Yield ◽  
Lewis Acidity ◽  
Benzimidazole Derivatives ◽  
Ambient Conditions ◽  
Reaction Condition ◽  
Green Approach

Zinc sulfamate (Zn(NH2SO3)2 is a derivative of sulfamic acid (H3NSO3) which possesses “Lewis acidity” and finds well suited in a number of catalytic applications. The present paper describes an efficient, eco-friendly, and clean synthesis of 2-substituted benzimidazole derivatives by reacting diverse o-phenylenediamine with various substituted aromatic aldehydes using a catalytic amount of zinc sulfamate in ethanol at ambient temperature. As a result, 10 mol.% of Zinc sulfamate catalyst showed 92% of respective product yield with 100% conversion using short reaction period in ethanol. Meanwhile, effect of reaction parameters, such as amount of catalyst, different solvents, and reaction temperature on reaction product, was also studied. In addition, in the optimized reaction condition various substituted biological important benzimidazoles derivatives were prepared by using optimized reaction condition in good to efficient yield. In addition, possible reaction mechanism in the presence of zinc sulfamate for the preparation of benzimidazole derivative was sketched and discussed. The present green approach showed significances with faster reaction rate with inexpensive catalyst, which showed excellent and clean yield of benzimidazole in mild reaction condition with easy work-up procedure.

cis-Dioxomolybdenum(VI) Complexes Containing Chiral Ligands: Synthesis and Catalytic Application in Olefin Epoxidation

2011 ◽  
Vol 1 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Jose A. Brito ◽  
Nathalie Saffon ◽  
Montserrat Gomez ◽  
Beatriz Royo
Keyword(s):  
Chiral Ligands ◽  
Olefin Epoxidation ◽  
Catalytic Application

The effect of steric size of leaving group on rates of the competing syn- and anti-pathways in biomolecular elimination

1980 ◽  
Vol 45 (8) ◽  
pp. 2171-2178
Author(s):  
Jiří Závada ◽  
Magdalena Pánková
Keyword(s):  
Comparative Analysis ◽  
Homologous Series ◽  
Leaving Group ◽  
Leaving Groups

Approximate rates of the competing syn- and anti-pathways have been determined in t-C4H9OK-t-C4H9OH promoted elimination from two homologous series of tosylates: I-OTs trans-III (R = H, CH3, C2H5, n-C3H7, i-C3H7, t-C4H9) and II-OTs trans-IV (R = CH3, C2H5, n-C3H7, i-C3H7, t-C4H9). A comparison has been made with rates of the same processes in the (+) elimination of the corresponding trimethylammonium salts I-N(CH3)3 trans-III and (+) II-N(CH3)3 trans-IV. The title effect is demonstrated by a comparative analysis of the rate patterns obtained for the two leaving groups.

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