Relative Nucleophilicity of the Two Sulfur Atoms in 1,5-Dithioglucopyranoside

1997 ◽  
Vol 36 (8) ◽  
pp. 868-870 ◽  
Author(s):  
Hideya Yuasa ◽  
Yujiro Kamata ◽  
Hironobu Hashimoto
Keyword(s):  
Relative Nucleophilicity

Relative Nucleophilicity: The Role of Solvation and Thermodynamics

1995 ◽  
Vol 117 (33) ◽  
pp. 8586-8593 ◽  
Author(s):  
Robert D. Bach ◽  
Julia E. Winter ◽  
Joseph J. W. McDouall
Keyword(s):  
Relative Nucleophilicity

scholarly journals Pd-Catalyzed C–N Coupling Reactions Facilitated by Organic Bases: Mechanistic Investigation Leads to Enhanced Reactivity in the Arylation of Weakly Binding Amines

2019 ◽  
Author(s):  
Joseph Dennis ◽  
Nicholas White ◽  
Richard Liu ◽  
Stephen L. Buchwald
Keyword(s):  
Heterogeneous Reaction ◽  
Negative Influence ◽  
Catalytic Cycle ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
Organic Bases ◽  
Cross Coupling Reactions ◽  
Mechanistic Investigation ◽  
Relative Nucleophilicity ◽  
The Many

The ability to use soluble organic amine bases in Pd-catalyzed C–N cross-coupling reactions has provided a long-awaited solution to the many issues associated with employing traditional, heterogeneous reaction conditions. However, little is known about the precise function of these bases in the catalytic cycle and about the effect of variations in base structure on catalyst reactivity. We used <sup>19</sup>F NMR to analyze the kinetic behavior of C–N coupling reactions facilitated by different organic bases. In the case of aniline coupling reactions employing DBU, the resting state was a DBU-bound oxidative addition complex, LPd(DBU)(Ar)X, and the reaction was found to be inhibited by base. In general, however, depending on the binding properties of the chosen organic base, increased concentration of the base can have a positive or negative influence on the reaction rate. We propose a model in which the turnover-limiting step of the catalytic cycle depends on the relative nucleophilicity of the base compared to that of the amine. This hypothesis guided the discovery of new reaction conditions for the coupling of weakly binding amines, including secondary aryl amines, which were unreactive nucleophiles in our original protocol.

Synthesis of α-Thiooximes by Addition of Thiols to N,N-Bis(oxy)-enamines: A Comparative Study of S-, N-, and O-Nucleo­philes in Michael Reaction with Nitrosoalkene Species

Synlett ◽  
2018 ◽  
Vol 29 (10) ◽  
pp. 1334-1339 ◽  
Author(s):  
Alexey Sukhorukov ◽  
Yana Naumovich ◽  
Aleksandr Kokuev ◽  
Sema Ioffe
Keyword(s):  
Comparative Study ◽  
Nucleophilic Addition ◽  
Michael Reaction ◽  
Lewis Base ◽  
Base Catalysis ◽  
Relative Reactivity ◽  
Efficient Manner ◽  
Highly Efficient ◽  
Relative Nucleophilicity ◽  
First Time

Nucleophilic addition of thiols to N,N-bis(oxy)enamines (nitrosoalkene acetals) produce valuable α-thiooximes in a highly efficient manner. The reaction was found to be solvent-dependent, likely because of distinct mechanisms operating in nonpolar and basic solvents (involving either Brønsted acid or Lewis base catalysis). By performing a series of competition experiments, the relative reactivity of S-, N-, and O-nucleophiles in reaction with N,N-bis(oxy)enamines was determined for the first time. Interestingly, the relative nucleophilicity was found to be highly dependent on the solvent, which allows regioselective control of these reactions by using an appropriate medium.

Intrinsic relative nucleophilicity of indoles

2016 ◽  
Vol 135 (8) ◽  
Author(s):  
Eduardo Chamorro ◽  
Mario Duque-Noreña ◽  
Mar Ríos-Gutiérrez ◽  
Luis R. Domingo ◽  
Patricia Pérez
Keyword(s):  
Relative Nucleophilicity
Sign in / Sign up

Export Citation Format

Share Document