Chiral β-Aryl-1H-1, 2, 4-Triazole: Synthesis And Biological Activity

Heterocyclic compounds widely exist in the nature with widespread biological activities,which attract scientist's interests significantly.Triazole derivatives are one of the most important families in heterocyclic compounds,and many of them have been used as medicine and pesticide.In case of pesticide industry,many of the most widely prescribed pesticides have optical isomers.At present,there are approximate 650 pesticides on market among which about one-third have optical enantiomers,but an important percentage are produced,marketed and used in the form of racemates.The presence of a non-active or less active stereoisomer just contributes to increase the levels of pollution without any benefit on the desired action.Since it is well known that a pair of enantiomers can display different biological activities,most of triazole pesticides have stereogenic centers lead to important consequences regarding their bioactivity.Herein report the design,distereoselective synthesize by using chiral auxiliary(Oppolzer's sultam)and investigate the in vitro fungicidal activities of novel chiralβ-aryl-1H-1,2, 4-triazole derivatives,which will be described as following:1.The recent progress about triazole using in the fields of medicine and pesticide was summarized.2.Series of chiralβ-aryl-1H-1,2,4-triazole derivatives were distereoselective synthesized. All the pure 2R and 2Sβ-aryl-1H-1,2,4-triazole derivatives were obtained conveniently by using chiral auxiliary(Oppolzer's sultam),and the ee value of the triazoles up to 99%. The structures are unequivocally confirmed by spectroscopic(1H and ¹³C NMR)data,EI MS and elemental analyses.Thirty intermediates were obtained as well,two of them have been characterized by X-ray crystal diffraction technique.3.All chiralβ-aryl-1H-1,2,4-triazole derivatives showed good inhibition to Fusarium oxysporium,Rhizoctoniasolani,Botrytiscinereapers,Gibberella zeae,Dothiorella gregaria,Colletotriehum gossypii.R and S enantiomers displayed different fungicidal activities to the same bacteria,the biological activities of some compounds were higher than Bayleton.