From Carbodiimides to Carbon Dioxide: Quantification of the Electrophilic Reactivities of Heteroallenes.

  title={From Carbodiimides to Carbon Dioxide: Quantification of the Electrophilic Reactivities of Heteroallenes.},
  author={Zhen Li and Robert J. Mayer and Armin R. Ofial and Herbert Mayr},
  journal={Journal of the American Chemical Society},
Kinetics of the reactions of isocyanates, isothiocyanates, carbodiimides, carbon disulfide, and carbon dioxide with carbanions or enamines (reference nucleophiles) have been measured photometrically in acetonitrile or DMSO solution at 20 °C. The resulting second-order rate constants and the previously published reactivity parameters N and sN of the reference nucleophiles were substituted into the correlation log k2(20 °C) = sN(N + E) to determine the electrophilicity parameters of the… 

Nucleophilic Magnesium Silanide and Silaamidinate Derivatives.

DFT calculations demonstrate that the previously reported reaction of [(BDI)Mg-n-Bu] with the silaborane Me2PhSi-Bpin provides the magnesium silanide derivative, through the intermediacy of a short-lived silyl-pinacolato-organoborate species, to be a consequence of the enhanced electrophilicity of the N-aryl-substituted carbodiimide reagent.

Cyclobutadiene Rhodium Complexes as Catalysts for the Synthesis of Amides from Electron‐rich Arenes, Tosyl Azide and CO

Cyclobutadiene rhodium complexes [(C4R4)RhX]2 (R=Et, Ph; X=I, Cl) at 0.5 mol % loading catalyze the formation of aromatic amides from various indoles, tosyl azide, and carbon monoxide (1 atm). The

Basicity as a Thermodynamic Descriptor of Carbanions Reactivity with Carbon Dioxide: Application to the Carboxylation of α,β-Unsaturated Ketones

The utilization of carbon dioxide as a raw material represents nowadays an appealing strategy in the renewable energy, organic synthesis, and green chemistry fields. Besides reduction strategies,

Structure-Property Relationships in Benzofurazan Derivatives: A Combined Experimental and DFT/TD-DFT Investigation

In this work we seek to understand and to quantify the reactivity of benzofurazan derivatives toward secondary cyclic amines, like pyrrolidine, piperidine and morpholine, acting as nucleophile groups

Polyurethanes from Direct Organocatalytic Copolymerization of p-Tosyl Isocyanate with Epoxides.

The direct copolymerization of p -tosyl isocyanate (TSI) with epoxides, initiated by onium salts in the presence of trialkylborane, to produce polyurethanes is reported. The rate of copolymerization

Computational Insights into Malononitrile-Based Carbanions for CO2 Capture.

Although anionic N and O sites have been widely used in chemisorption of CO2, carbanions are much less explored for CO2 capture. Here we employ ab initio calculations and quantum mechanical/molecular

CO2 Chemisorption Behavior in Conjugated Carbanion-Derived Ionic Liquids via Carboxylic Acid Formation.

Superbase-derived task-specific ionic liquids (STSILs) represent one of the most attractive and extensively studied systems in carbon capture via chemisorption, in which the obtained CO2 uptake

Quasi-Living Copolymerization of Aryl Isocyanates and Epoxides.

Nontraditional polyurethane (PU) has been successfully synthesized by anionic copolymerization of some typical aryl isocyanates and epoxides with ammonium halide onium salt (Lewis base) as the



Nucleophilic Reactivities of Azulene and Fulvenes

The kinetics of the reactions of azulene (1), 6,6-dimethylfulvene (2), 6-[4-(dimethylamino)phenyl]fulvene (3) and 6-(julolidin-9-yl)fulvene (4) with a set of benzhydrylium ions (reference

Nucleophilic Reactivities of Bis-Acceptor-Substituted Benzyl Anions

The kinetics of the reactions of bis-acceptor-substituted benzyl anions (PhCXY-, X, Y = CN, CO2Et, COPh, SO2Ph) with benzhydrylium ions and quinone methides (reference electrophiles) have been

Nucleophilic reactivities of indoles.

The kinetics of the coupling of 2 with a large variety of indole structures have been studied in acetonitrile, leading to a ranking of this family of pi-excessive carbon nucleophiles over a large domain of the nucleophilicity scale N.

Kinetics of Electrophilic Fluorinations of Enamines and Carbanions: Comparison of the Fluorinating Power of N-F Reagents.

It is shown that the electrophilicity parameters E reported in this work are able to rationalize known fluorination reactions and are, therefore, recommended as guide for designing new electrophilic fluorinations.

Quantification and Theoretical Analysis of the Electrophilicities of Michael Acceptors.

Good correlations were found between the experimentally observed electrophilic reactivities of 44 Michael acceptors and their calculated methyl anion affinities, particularly when solvation by dimethyl sulfoxide was taken into account by applying the SMD continuum solvation model.

Nucleophilic reactivities of benzenesulfonyl-substituted carbanions.

Kinetics of the reactions of four benzenesulfonyl-stabilized carbanions with reference electrophiles have been determined and the additions of (1a-d)- to ordinary Michael acceptors were found to be 5-24 times slower than predicted by eqn (1).

π-Nucleophilicity in Carbon−Carbon Bond-Forming Reactions

Which electrophiles react with which nucleophiles? The correlation log k20 °C = s(E + N), in which electrophiles (carbocations, metal-π-complexes, diazonium ions) are characterized by one (E) and

Reference scales for the characterization of cationic electrophiles and neutral nucleophiles.

The reactivity parameters in Figure 3 are recommended for the characterization of any new electrophiles and nucleophiles in the reactivity range covered and are suitable for characterizing the nucleophilic reactivities of alkynes, metal-pi-complexes, and hydride donors.

Kinetics and Mechanism of Oxirane Formation by Darzens Condensation of Ketones: Quantification of the Electrophilicities of Ketones.

Density functional theory calculations of the intrinsic reaction pathways showed that the reactions of the ketones 1 with the chloromethyl anions 2 yield two rotational isomers of the intermediate halohydrin anions 4, only one of which can cyclize while the other undergoes retroaddition because the barrier for rotation is higher than that for reversal to the reactants 1 and 2.

Which Factors Control the Nucleophilic Reactivities of Enamines?

The synthesis, structures, and properties of deoxybenzoin-derived enamines ArCH=C(Ph)NR2 , which have been designed as reference nucleophiles for the future quantification of electrophilic reactions, are explicitly described.