Nitroalkanes, acidities of

This phenomenon was attributed to the lower kinetic acidity of nitroalkanes. Dipolar aprotic solvents can be used with aryllead reagents to conduct the arylations, as the deprotonation is accelerated in these solvents. The reactions are preferably performed in DMSO. As DMSO forms strong complexes with organolead compounds, the presence of pyridine or any other complexing base is not required and the reaction proceeded smoothly at 40 C in 30 hours to afford good yields of the a-arylated derivatives. 

Solubility, thermodynamic and kinetic acidities of nitroalkanes are of great importance in the course of the reaction, but the hydrophobic effect (Lubineau et al., 1994a) could be involved, since additives such as glucose or saccharose accelerate the reaction even more (Lubineau and Aug6, 1992). Amphiphilic molecules can also influence the hydrophobic interactions. In fact, cetyltrimethylammonium chloride (CTACl) as cationic surfactant promoted the Michael reaction of various nitroalkanes with conjugated enones in dilute aqueous solutions of sodium hydroxide (Ballini and Bosica, 1996) ... 

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