Chemistry of polyhalogenated nitrobutadienes, 3: [4+2] cycloadditions of (Z)-1,1,4-trichloro-2,4-dinitrobuta-1,3-diene and subsequent reactions

摘要

The multifaceted chemical behavior of polyhalogenated nitrobutadienes, such as 1 and 2, inspired us to test their features in [4+2] cycloaddition reactions. It appears that in the presence of an appropriate diene only the beta-chloro-beta-nitro vinyl moiety of 1 acts as an efficient dienophile. The resulting cycloaddition products were subsequently converted at the beta,beta-dichloro position by means of a suitable N,O- and N,N-bisnucleophile to give benzoxazole or benzimidazole derivatives. The latter reaction products proved valuable for crop protection.