-An oxetane ring can be constructed from 5 α-acyloxy-Δ4(20) -taxoids with osmylation as the first step in the usual manner. The innovation reported here is the use of an intramolecularly available acyl group for the...-An oxetane ring can be constructed from 5 α-acyloxy-Δ4(20) -taxoids with osmylation as the first step in the usual manner. The innovation reported here is the use of an intramolecularly available acyl group for the protection of 20-OH by an unexpected 5-to 20-migration under slightly basic conditions.展开更多
A series of novel cis-nitenpyram analogues bearing acyloxy segments anchored on the tetrahydropyrimi-dine ring was designed and synthesized. Preliminary bioassays indicate that all the nitenpyram analogues 3a--3n exhi...A series of novel cis-nitenpyram analogues bearing acyloxy segments anchored on the tetrahydropyrimi-dine ring was designed and synthesized. Preliminary bioassays indicate that all the nitenpyram analogues 3a--3n exhibit good insecticidal activities against Nilaparvata lugens and Aphis medicaginis at 100 mg/L, while analogue 3k affords the best activity in vitro and the lethal concentration 50（LC50） values（0.187, 0.214 mg/L） are close to that of nitenpyram. The structure activity relationships（SARs） suggest that their insecticidal potency is influenced by the species of acyloxy segments. The docking results reveal that analogue 3k forms stronger hydrogen-bonding with the nAChR, which explain the structure activity relationships（SARs） observed in vitro and imply that the strategies of our designed nitenpyram analogues are feasible.展开更多
文摘-An oxetane ring can be constructed from 5 α-acyloxy-Δ4(20) -taxoids with osmylation as the first step in the usual manner. The innovation reported here is the use of an intramolecularly available acyl group for the protection of 20-OH by an unexpected 5-to 20-migration under slightly basic conditions.
基金Supported by the National Natural Science Foundation of China（Nos.21042010, 21102092 and 30870560）, the Key Scientific ＂Twelfth Five-Year＂ National Technology Support Program, China（No.2011BAE06B01-17）, the Innovation Project of Shanghai Education Commission, China（No. 12YZ078）, the Program of the Food Safety and Nutrition Innovation Team of Shanghai Normal University, China（No.DXL123） and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, China（No.07dz22303）.
文摘A series of novel cis-nitenpyram analogues bearing acyloxy segments anchored on the tetrahydropyrimi-dine ring was designed and synthesized. Preliminary bioassays indicate that all the nitenpyram analogues 3a--3n exhibit good insecticidal activities against Nilaparvata lugens and Aphis medicaginis at 100 mg/L, while analogue 3k affords the best activity in vitro and the lethal concentration 50（LC50） values（0.187, 0.214 mg/L） are close to that of nitenpyram. The structure activity relationships（SARs） suggest that their insecticidal potency is influenced by the species of acyloxy segments. The docking results reveal that analogue 3k forms stronger hydrogen-bonding with the nAChR, which explain the structure activity relationships（SARs） observed in vitro and imply that the strategies of our designed nitenpyram analogues are feasible.
