New route to functionalized cyclohexenes from nitromethane and electrophilic alkenes without solvent under focused microwave irradiation

Conjugate Additions of Nitroalkanes to Electron-Poor Alkenes: Recent Results

“…In fact, nonionic bases such as P(RNCH 2 CH 2 ) 3 N (Verkade's bases) 50 work quite efficiently in a number of examples but their widespread utilization has been hampered by the fact that some of these reagents have become commercially available only recently. Activating techniques such as microwave or ultrasound irradiation may improve the efficiency of known catalysts, especially those working in heterogeneous and solventless conditions. ,,, In this context, it is interesting to observe that almost all the newly introduced catalysts belong to the class of solid supports that in many instances present consistent advantages over soluble bases. For particularly reactive nitro derivatives, such as α-nitro ketones or esters, mild bases can be used and cyclic α-nitro ketones react even in water without the need of any added base .…”

New Solvent-Free Organic Synthesis Using Focused Microwaves

“…In the presence of adjusted amounts of piperidine, methylbenzylidene cyanoacetate (21) reacts with nitromethane to give cyclohexenes 22 and 23 according to the reaction conditions 80 (Scheme 21).…”

The Recycling of Substandard Rocket Fuel N,N-Dimethylhydrazine via the Involvement of Its Hydrazones Derived from Glyoxal, Acrolein, Metacrolein, Crotonaldehyde, and Formaldehyde in Organic Synthesis

“…Furthermore, the phenyl hydrazone derivative 68a undergoes cyclization via methyl alcohol elimination under MWI catalysis, resulting in the formation of N-phenylpyridazine 69a. Interesting chemical transformations (Figure 12) are presented in publication [62], which explores solvent-free and pipyridine-catalyzed reactions under microwave irradiation (MWI), an effective method for dry organic syntheses [63][64][65][66][67][68][69][70][71][72]. Phenylhydrazone (HGa) and dimethylhydrazone (HGb) react with acetoacetic ether in a 1:1 ratio to form conjugated compounds 68a and 68b.…”