Natural isoquinolinium alkaloids possess a wide range of biological activities.The design and synthesis of mesoionic isoquinoliniums is of great importance.This paper reports the synthesis of unique mesoionic thiazolo...Natural isoquinolinium alkaloids possess a wide range of biological activities.The design and synthesis of mesoionic isoquinoliniums is of great importance.This paper reports the synthesis of unique mesoionic thiazoloisoquinolinium thiolates stabilized by aromatization and 1,3-dipolarization.Such compounds can be synthesized via the three component [2 + 2 + 1] cycloaddition reaction of isoquinolines with ethyl propionate and elemental sulfur in the absence of any metal catalyst and additives.Importantly,thiazoloisoquinolinium thiolates can be transformed to thioether-containing thiazoloisoquinolinium halides.A selective [4 + 2] cycloaddition can also be used to form S-bridged fused tetracyclic compounds with a thiothiamide ring unit and two quarternary carbon centres.Compound I-1 shows good bioactivity against the chlorophyll of duckweed(Lemna minor) with inhibition rate of 51.5 mg/mL.展开更多
基金financially supported by Natural Science Foundation of Guangdong Province for Distinguished Young Scholars (Nos.2019B151502052, 2021B1515020107)the programs of National Natural Science Foundation of China (No.32072450)+2 种基金the International Science and Technology Cooperation Program in Guangdong (No.2020A0505100048)the Program of Science and Technology of Guangzhou (No.202002030295)the open Project of the State Key Laboratory of Crop Stress Biology for Arid Areas (No.CSBAAKF2021009)。
文摘Natural isoquinolinium alkaloids possess a wide range of biological activities.The design and synthesis of mesoionic isoquinoliniums is of great importance.This paper reports the synthesis of unique mesoionic thiazoloisoquinolinium thiolates stabilized by aromatization and 1,3-dipolarization.Such compounds can be synthesized via the three component [2 + 2 + 1] cycloaddition reaction of isoquinolines with ethyl propionate and elemental sulfur in the absence of any metal catalyst and additives.Importantly,thiazoloisoquinolinium thiolates can be transformed to thioether-containing thiazoloisoquinolinium halides.A selective [4 + 2] cycloaddition can also be used to form S-bridged fused tetracyclic compounds with a thiothiamide ring unit and two quarternary carbon centres.Compound I-1 shows good bioactivity against the chlorophyll of duckweed(Lemna minor) with inhibition rate of 51.5 mg/mL.
