An Efficient Route to Isochromene Derivatives via Cascade Radical Cyclization and Radical-Radical Coupling
By: Yu, Kaili; Li, Minyan; Deng, Guogang; Liu, Chunxiang; Wang, Jing; Liu, Zhengfen; Zhang, Hongbin; Yang, Xiaodong; Walsh, Patrick J.
ADVANCED SYNTHESIS & CATALYSIS
Early Access: JULY 2019
Isochromenes are important pharmacophores present in biologically active molecules and natural products. Their synthesis is generally limited to cyclization of phenyl propargyl ether precursors under transition metal catalyzed conditions. Herein, we present a novel disconnection that rapidly constructs isochromene derivatives through a cascade radical cyclization strategy. Generation of aryl radicals by SET reduction of 2-iodo benzyl allenyl ethers is followed by radical cyclization to construct the isochromene core with formation of an allylic radical. The allylic radical then undergoes coupling with the azaallyl radical to give products in good to excellent yields. The elaborated 2-iodo phenyl propargyl ether precursors can be used to construct isochromenes bearing various functional groups.
Author Keywords:Cascade reactions; Radical coupling; Radical cyclization; Isochromene; Azaallyl anions
KeyWords Plus:SUPER-ELECTRON-DONORS; CYCLIC ALKENYL ETHERS; ALKYNES; SILVER; ALKYNYLBENZALDEHYDES; DISCOVERY; CATALYST; ACID
[ 1 ] Yunnan Univ, Sch Chem Sci & Technol, Minist Educ & Yunnan Prov, Key Lab Med Chem Nat Resources, Kunming 650091, Yunnan, Peoples R China
[ 2 ] Univ Penn, Penn Merck Lab High Throughput Expt, Dept Chem, Roy & Diana Vagelos Labs, Philadelphia, PA 19104 USA
上一條：【論文發表】Synthesis and antitumor activity of aza-brazilan derivatives containing imidazolium salt pharmacophores
下一條：【論文發表】Retro-biosynthetic construction of corynanthe alkaloid skeletons from rhynchophylline alkaloids