摘要
A mild synthetic method of a series of phenanthrenes with different substituents on the phenanthrene ring is described.The method involves intramolecular oxidative coupling with 2,3-dichloro-5,6-dicyanobenzoquinone （DDQ）/trifluoroacetic acid（TFA） as oxidant to produce phenanthrenes in high yields and is fit for large-scale preparation.Furthermore,DDQ can be regenerated by a simple oxidation.The present approach solves a key step for the synthesis of polycyclic structures related to an alkaloid tylophorine.
A mild synthetic method of a series of phenanthrenes with different substituents on the phenanthrene ring is described.The method involves intramolecular oxidative coupling with 2,3-dichloro-5,6-dicyanobenzoquinone （DDQ）/trifluoroacetic acid（TFA） as oxidant to produce phenanthrenes in high yields and is fit for large-scale preparation.Furthermore,DDQ can be regenerated by a simple oxidation.The present approach solves a key step for the synthesis of polycyclic structures related to an alkaloid tylophorine.
基金
Supported by the National Key Project for Basic Research of China（No.2010CB126100）, the National Natural Science Foundation of China（Nos.21132003, 21121002, 21372131） and the Specialized Research Fund for the Doctoral Program of Higher Education of China（No.20120031110010）.
