Nitroalkanes unsaturated bonds

In the addition of nitromethane with group containing a double bond, hydrogen atoms of nitroalkane are usually added to the atom of double bonds with less hydrogen atoms, but the opposite results will be obtained with the presence of unsaturated ethers. In the addition reaction between an unsaturated compound with conjugated double bonds and an nitroalkane, double bonds will be isomerized. 

Michael condensations, together with the Diels-Alder cycloaddition and the aldol reactions, are the most powerful and useful bond-fonning reactions in synthetic organic chemistry. Like the nitro-aldol (Henry) additions, nitroalkanes are particularly appropriate reagents in Michael reactions they act as a-hydrogen donors. Nitroalkanes react easily with typical Michael acceptors such as a,p-unsaturated aldehydes or ketones under base or Lewis acid catalysis. ... 

A in the equation represents a substituted aldehyde. An electron withdrawing group can activate the double bond and its the electron-withdrawing capability is related to the produced electronegativity, which are usually believed that nitro is the strongest followed by sulfonic acid group [20]. The double bond is between the substituted a, P carbons, a, P-Unsaturated carboxylic acids, carboxylic acid esters, nitriles, acids, ketones, sulfones, aldehydes, ethers, olefins and heterocyclic alkene can all react with nitroalkane via addition reactions to form the corresponding nitro-derivatives. 

Nitroalkanes may also react with carbon-nitrogen double bond and nitrogen-nitrogen double bond via addition reaction to form nitroalkylamines and unsaturated nitro compounds [21]. 

Detoxication mechanisms employed by the lower termites Prorhino-termes simplex and Schedorhinotermes lamanianus were investigated. Soldiers of these two species secrete nitroalkanes and vinyl ketones, respectively, in response to colony disturbance. Workers of these termites die when exposed to the volatiles of the other species, but survive when exposed to volatiles from conspecific soldiers (529). The workers have substrate-specific alkene reductases which, in the presence of a reduced cofactor, catalyze the reduction of the electron-deficient double bond of the unsaturated eletrophilic group. The alkanes are then recycled in vivo to acetate (see Fig. 2). 

The reduction of carbon-carbon double bonds to single bonds has been studied with various substrates. For example, Ohta et al. demonstrated that the reduction of a number of 1-nitro-l-alkenes by fermenting baker s yeast was enantioselective, resulting in the formation of optically active 1-nitroalkanes as shown in Fig. 10.13(a).On the other hand, Fuganti et al. reduced a,/3-unsaturated y-lactones to produce enantiomerically pure (-1-)-(J )-goniothalamin (Fig. 10.13(b)), which shows central nervous system activity. They also performed the kinetic resolution of the corresponding embryotoxic epoxide with yeast. 8... 

Trimethylsilyl enol ethers of acyclic and alicyclic ketones add to a)S-unsaturated nitroalkanes in Michael fashion under Lewis acid catalysis. Direct hydrolysis of the crude product leads to good yields of 1,4-diones.The ease of access to the starting materials, the high regioselectivity of the addition (the reaction conditions do not cause migration of the double bond in the enol ether), and the simplicity of the manipulations involved underline the usefulness of the method (Scheme 15, p. 83). 

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