Intramolecular annulation of aromatic rings with N-sulfonyl 1,2,3-triazoles: divergent synthesis of 3-methylene-2,3-dihydrobenzofurans and 3-methylene-2,3-dihydroindoles
作者:Xiang-Ying Tang、Yong-Sheng Zhang、Lv He、Yin Wei、Min Shi
DOI:10.1039/c4cc08343a
日期:——
The controllable synthesis of 3-methylene-2,3-dihydrobenzofurans2and 3-methylene-2,3-dihydroindoles5has been developed via cycloisomerization of N/O-tethered aryltriazoles.
Synergists were used to diagnose possible mechanisms of permethrin resistance in permethrin-selected strains of the tobacco budworm, Heliothis virescens (F.). In addition to permethrin, these strains of the tobacco budworm were resistant to alpha-cyano-pyrethroid insecticides, organophosphorus insecticides and DDT. The monooxygenase-inhibiting prop-2-ynyl aryl ethers were the only effective synergists of permethrin among 16 candidates tested. The most effective synergist was 1,2,4-trichloro-3-(2-propynyloxy)benzene. Piperonyl butoxide, a common monooxygenase-inhibiting synergist in other species and tobacco budworm strains, was inactive. These results suggested the presence and contribution of an unusual monooxygenase in the enzymatic detoxication of permethrin. DDT cross-resistance, which was not synergized, and broad pyrethroid cross-resistance supported previous evidence for target site insensitivity as a second pyrethroid-resistance mechanism in these strains. The actions of S,S,S-tributyl phosphorotrithioate (TBPT) and triphenyl phosphate (TPP) suggested that hydrolytic detoxication, important in methyl parathion-resistance tobacco budworm strains, had little or no role in conferring pyrethroid resistance in these strains.
Diphenyl-Diselenide-Mediated Domino Claisen-Type Rearrangement/Cyclization of Propargylic Aryl Ethers: Synthesis of Naphthofuran-2-carboxaldehyde Derivatives
作者:Jun-Dan Fang、Xiao-Biao Yan、Wu-Jie Lin、Yi-Chuan Zhao、Xue-Yuan Liu
DOI:10.1021/acs.orglett.9b02942
日期:2019.9.20
A diphenyl-diselenide-mediated Claisen-type rearrangement/cyclization of propargylic arylethers under metal-free conditions is developed, affording various naphthofuran-2-carboxaldehydes in moderate to excellent yield. The broad substrate scope and excellent functional group compatibility suggest that it can be a straightforward and powerful method to access naphthofuran-2-carboxaldehydes in a highly