Sulfonyl radical-enabled 6-endo-trig cyclization for regiospecific synthesis of unsymmetrical diaryl sulfones

Rong Fu, Wen-Juan Hao,* Ya-Nan Wu, Nan-Nan Wang, Shu-Jiang Tu,* Guigen Li, and Bo Jiang*

A new sulfonyl radical-triggered 6-endo-trig cyclization of unactivated 1,5-enynes under catalytic oxidation conditionsfor flexible synthesis of unprecedented unsymmetrical diaryl sulfones has been established. Using 2-arylalkynyl-1,1'-biphenyls, this transformation could also proceed smoothly, delivering new sulfonylated phenanthrenes.The synthetic utility of these transformations results in subsequent C−S and C−C bond-forming reactions to effectively build up functional sulfones with potential significance.

Org.  Chem. Front. 2016,  3, 1452-1456