Nucleofugality hierarchy, in the aminolysis reaction of 4-cyanophenyl 4-nitrophenyl carbonate and thionocarbonate. Experimental and theoretical study

The kinetics of quinuclidine displacement of BH3 from a wide range of Lewis base borane adducts have been measured. Parameterization of these rates has enabled the development of a nucleofugality scale (N F B), shown to quantify and predict the leaving group ability of a range of other Lewis bases. Additivity observed across a number of series R′3–n R n X (X = P, N; R′ = aryl, alkyl) has allowed the formulation of related substituent parameters (n f PB, n f AB), providing a means of calculating N F B values for a range of Lewis bases that extends far beyond those experimentally derived. The utility of the nucleofugality parameter is explored by the correlation of the substituent parameter n f PB with the hydrolyses rates of a series of alkyl and aryl MIDA boronates under neutral conditions. This has allowed the identification of MIDA boronates with heteroatoms proximal to the reacting center, showing unusual kinetic lability or stability to hydrolysis.

show abstract

A Lewis Base Nucleofugality Parameter, N^F_B, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics

Taylor

González

Nichol

et al. 2021

J. Org. Chem.

View full text Add to dashboard Cite

show abstract

Kinetic study on pyridinolysis of aryl benzenesulfonates: factors governing regioselectivity and reaction mechanism

Jung

Dust

2022

Can. J. Chem.

View full text Add to dashboard Cite

A kinetic study is reported for reactions of 2,4-dinitrophenyl X-substituted-benzenesulfonates (1a-1f) and Y-substituted-phenyl benzenesulfonates (2a-2f) with Z-substituted-pyridines. The reactions proceed through S‒O and C‒O bond scissions competitively. The Yukawa-Tsuno plot for the reactions of 1a-1f with 4-oxypyridine (S‒O bond fission) exhibits an excellent linearity. The Brønsted-type plot for the reactions of 2,4-dinitrophenyl benzenesulfonate (1d) with pyridines (S‒O bond fission) is also linear with βnuc = 0.62. The Brønsted-type plot for the reactions of 2a-2f with 4-oxypyridines (S‒O bond fission) is linear with βlg= ‒1.17. Thus, the reactions have been concluded to proceed through a concerted mechanism, in which leaving-group expulsion is significantly more advanced than bond formation between the electrophilic center and nucleophile at the transition state. The Hammett plot for the reactions of 1a-1f with 4-oxypyridine (C‒O bond fission) exhibits scattered points with ρX= 0.98. The Brønsted-type plot for the reactions of 1d with Z-substituted-pyridines (C‒O bond fission) results in an excellent linear correlation with βnuc = 0.38. Thus, the reactions (C‒O bond fission) have been concluded to proceed through a stepwise mechanism with a Meisenheimer complex, in which expulsion of the leaving group occurs after the rate-determining step. Factors governing regioselectivity and reaction mechanism are discussed.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Nucleofugality hierarchy, in the aminolysis reaction of 4-cyanophenyl 4-nitrophenyl carbonate and thionocarbonate. Experimental and theoretical study

Abstract: Nucleophilic substitution reactions of title compounds have been investigated with a series of secondary alicyclic amines in several solvents. The solvent, amine, and electrophilic group effects on kinetics, mechanism and...

Cited by 2 publications

References 59 publications

A Lewis Base Nucleofugality Parameter, N^F_B, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics

A Lewis Base Nucleofugality Parameter, N^F_B, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics

Kinetic study on pyridinolysis of aryl benzenesulfonates: factors governing regioselectivity and reaction mechanism

Contact Info

Product

Resources

About

Nucleofugality hierarchy, in the aminolysis reaction of 4-cyanophenyl 4-nitrophenyl carbonate and thionocarbonate. Experimental and theoretical study

Abstract: Nucleophilic substitution reactions of title compounds have been investigated with a series of secondary alicyclic amines in several solvents. The solvent, amine, and electrophilic group effects on kinetics, mechanism and...

Cited by 2 publications

References 59 publications

A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics

A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics

Kinetic study on pyridinolysis of aryl benzenesulfonates: factors governing regioselectivity and reaction mechanism

Contact Info

Product

Resources

About

A Lewis Base Nucleofugality Parameter, N^F_B, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics

A Lewis Base Nucleofugality Parameter, N^F_B, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics