24601-55-6

Upstream product

• 623-73-4 diazoacetic acid ethyl ester 
• 4714-21-0 E-1-methyl-4-styryl-benzene 
• 104-87-0 4-methyl-benzaldehyde 
• 6921-34-2 benzylmagnesium chloride 
• 1100-88-5 benzyltriphenylphosphonium chloride 
• 20498-63-9 1-(4-methylphenyl)-2-phenylethanol 

Downstream Products

• 21760-13-4 (E)-2-phenyl-3-p-tolylcyclopropanecarboxylic acid 
• 32092-99-2 1-methyl-4-(3-phenylpropa-1,2-dienyl)benzene 
• 143959-16-4 1-((1R,3R)-2-Methoxy-3-phenyl-cyclopropyl)-4-methyl-benzene 
• 143958-96-7 ethyl N-((E)-2-phenyl-3-p-tolylcyclopropyl)carbamate 
• 143959-05-1 ethyl N-nitroso-N-((E)-2-phenyl-3-p-tolylcyclopropyl)carbamate 

Relevant academic research and scientific papers

Mechanistic criteria for cation radical reactions: Aminium salt-catalyzed cyclopropanation

Mechanistic studies of the cyclopropanation of a series of trans-stilbenes by ethyl diazoacetate catalyzed by two different triarylaminium salts decisively confirm a cation radical mechanism and rule out a hypothetical electrophilic mechanism. The elucidation of key aspects of these cation radical mechanisms, including kinetic vs equilibrium control of ionization and chain vs catalytic mechanisms, has also been achieved for these systems. New mechanistic criteria for the positive identification of cation radical mechanisms are proposed.

Electron Demand in the Transition State of the Cyclopropylidene to Allene Ring Opening

The electronic structure of the transition state for the cyclopropylidene to allene conversion has been probed.The methodology involved the relative rates of ring opening vs trapping by MeOH for a series of variously substituted 2,3-diarylcyclopropylidenes.With the assumption that the rate of trapping was unaffected by substituents, a Hammett correlation was constructed.The negative value (-0.72) for ρ indicated that the carbenic center attracts electron density in the ring-opening transition state, much like the cyclopropyl cation to allyl cation transition state.Temperature-dependent studies showed that the observed preference for ring opening was driven by entropy factors.Also, using reasonable estimates for the close to diffusion-controlled trapping activation enthalpies, the derived enthalpies for ring opening were in close agreement with the best theoretical values.