1413809-89-8Relevant articles and documents
5-hydroxyindoles by intramolecular alkynol-furan diels-alder cycloaddition
LaPorte, Matthew,Hong, Ki Bum,Xu, Jie,Wipf, Peter
, p. 167 - 174 (2013/03/29)
A convergent approach provides a convenient access to synthetically and biologically useful 3,4-disubstituted 5-hydroxyindoles. The one-pot procedure uses microwave heating to initiate an intramolecular [4 + 2]-cycloaddition of an alkynol segment onto a furan followed by a fragmentation, aromatization, and N-Boc deprotection cascade. Yields range from 15 to 74%, with aromatic substituents providing better conversions. 4-Trimethylsilylated analogues undergo a 1,3-silatropic rearrangement to give the O-TMS ethers.