P-nitroacrylates

Esters and ketones bearing P-nitro groups can be prepared in many ways. For example, the Diels-Alder reaction of methyl P-nitroacrylate is one typical case. Various cyclic dienes are prepared by this route, and the reactions of Eq. 7.121167 andEq. 7.122168 are exemplified. 

Another approach is the Michael addition to ethyl P-nitroacrylate, as shown in Eq. 7.123, which has been used in the synthesis of a-methylenebutyrolactone, a moiety characteristic of many sesquiterpenes.169... 

Functionalized nitroalkenes are important dienophiles in the Diels-Alder reaction. For example, ( )-methyl P-nitroacrylate is an important reagent in organic synthesis. The nitro group can be readily eliminated the Diels-Alder reaction of P-nitroacrylate is equivalent to that of ethyl propiolate with an inverse regiochemistry (Eq. 8.4).11... 

Scheme 4.68 Enantioselective sulfa-Michael reaction of arylthiols with a-aryl-P-nitroacrylates.

Scheme 6.67 Ni(Cl04)2/bisoxazoline 147 complex catalyzed AFC alkylation of indoles with P-CFj-p-disubstituted nitroalkenes 148 and acyclic a-substituted-P-nitroacrylates 149 reported by Jia.

Yoshida developed an enantioselective Michael addition reaction of a-branched aldehydes to p-nitroacrylates by using a primary a-amino acid, L-phenylalanine (Phe-OH), lithium salt 14 (Scheme 2.9). The obtained p-formyl-p -nitroesters were transformed into the corresponding cyclic amino acids in high yields via hydrogenolysis on Pd/C. 

Scheme 2.9 Effect of olefin geometry on the organocatalyzed conjugate reduction of P-nitroacrylates...

A solid-supported carbonate reagent was used to initiate the formation of 2H-l,4-benzoxazin-2-ones 303 from P-nitroacrylate 301 and 2-aminophenol 302 (Scheme 7.72) [154]. This hetero-Michael addition/intramolecular transesteri-fication/elimination of HN03/[l,3]-proton shift domino reaction proceeded in moderate to excellent yields. In another study, a series of various functionalized pyrrolo[l,2-r]pyrazines 305 were made synthetically available through the reaction of vinyl azides 304 and lH-2-pyrrolecarbaldehyde (Scheme 7.73). The deprotonated pyrrole initially reacts in a Michael manner with the vinyl azides, with nitrogen as... 

In continuing their studies on the synthesis of racemic C-nucleosides, Just and co-workers have reported the synthesis of DL-2 -deoxyshowdomycin (81) from furan and methyl P-nitroacrylate (Scheme 17), of a nitrogen analogue (82) of... 

An extension of this work was reported by the same research group using P-nitroacrylates 71 and the same thiourea organocatalyst 69 with the main aim of... 

Scheme 10.15 Friedel-Crafts reaction of indoles with a-substituted p-nitroacrylates.

Ballini R, Gabrielli S, Palmieri A (2009) P-Nitroacrylates as key starting materials for the uncatalysed one-pot synthesis of polyfunctionalized dihydroquinoxalinone derivatives, via an anti-Michael reaction. Synlett 6 965-967. doi 10.1055/s-0028-1088197... 

The one-pot, organocatalytic Hayashi sequential reaction (HSR) of p-nitroacrylate (806), aldehyde (807), toluenethiol (808), and vinylphosphonate (805) allowed the synthesis of highly functionaKsed cyclohexanes (809) with very high enantioselectivity (up to 99 % ee). The one-pot synthesis consisted of the tertiary amine modified diarylprolinol silyl ether (810)-mediated asymmetric Michael reaction, a domino Michael reaction/the Horner-Wadsworth Emmons reaction, and a sulfa-Michael reaction (Scheme 205). ... 

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