作者:Luisruben P. Martinez、Shigenobu Umemiya、Sarah E. Wengryniuk、Phil S. Baran
DOI:10.1021/jacs.6b04816
日期:2016.6.22
The structurally intriguing terpenes pallambins C and D have been assembled in only 11 steps from a cheap commodity chemical: furfuryl alcohol. This synthesis, which features a redox-economic approach free of protecting-group manipulations, assembles all four-ring systems via a sequential cyclization strategy. Of these four-ring constructing operations, two are classical (Robinson annulation and Mukaiyama
Homolytic substitution reactions of electron-rich pentatomic heteroaromatics by electrophilic carbon-centered radicals. Synthesis of .alpha.-heteroarylacetic acids
Efficient and selective homolytic substitutions (yields between 55 and 90%) of pyrrole, indole, and some pyrrole derivatives have been carried out using ambiphilic and electrophilic carbon centered radicals, generated in DMSO by Fe2+/H2O2 and alpha-cyano-, alpha-carbonyl-, and alpha,alpha'-dicarbonylalkyl iodides. The reaction is highly successful also with pyrroles substituted by electron-withdrawing groups, which has allowed an efficient synthesis of Tolmetin. A few extensions of this reaction to furan and thiophene are described.