【文章名】Stereoselective Electrocatalytic Cyclization of 4,4 '-(Arylmethylene)bis(1H-pyrazol-5-ols) to (5R*,6R*)-11-Aryl-4,10-dimethyl-2,8-diphenyl-2,3,8,9-tetra-azadispiro[4. 0.4.1]undeca-3,9-diene-1,7-diones
Stereoselective Electrocatalytic Cyclization of 4,4 '-(Arylmethylene)bis(1H-pyrazol-5-ols) to (5R*,6R*)-11-Aryl-4,10-dimethyl-2,8-diphenyl-2,3,8,9-tetra-azadispiro[4. 0.4.1]undeca-3,9-diene-1,7-diones
作者
ELINSON MICHAIL N; VERESHCHAGIN ANATOLII N; TRETYAKOVA EVGENIYA O; BUSHMARINOV IVAN S; NIKISHIN GENNADY I
[摘要]：Indirect electrochemical oxidation of 4,4'-(arylmethylene)bis(1H-pyrazol-5-ols) in methanol in an undivided cell in the presence of sodium bromide results in highly efficient formation of the corresponding bis(spiro-2,4-dihydro-3H-pyrazol-3-one)cyclopropanes with 85-96% substance yields and 70-80% current efficiency. NMR and single crystal X-ray diffraction indicate that the products are formed exclusively as (R*,R*)-isomers. The application of this effective indirect electrochemical approach to the corresponding pharmacologically promising bis(spiro-2,4-dihydro-3H-pyrazol-3-one) cyclopropanes allows facile and convenient reaction conditions, and is valuable from the viewpoint of environmentally benign synthesis and large-scale processes.
