Visible‐light Catalysed Trifluoromethylthiolation and Related Dearomative Spirocyclizations

Abstract

We conceptualized an efficient radical cyclization approach for the synthesis of SCF3, SAr, SO2Ar and COAr featured spirocyclic [4.5] and [5.5] trienone between biaryls and ArSO2H or ArCOCO2H in presence of RFTA as a photocatalyst whereas ArSSAr or AgSCF3 devoid of photocatalyst via an energetically demanding dearomative transformation under visible‐light catalysis. The unprecedented photo‐excited charge transfer complex with biaryl tethered ynones provides a way to promote S‐centered radical generation followed by its insertion to enable a wide range of biologically important molecules.

BF3·Et2O-assisted synthesis of sulfinylated spiro[5.5]trienones from biaryl ynones

“…8 Therefore, generation of spirocyclic cores, especially spiro[5.5]trienone, has always been fascinating to chemists. 9,10 Recently, Ackermann reported electro-oxidative 6-7-6-fused-ring-generating sulfonylation of biaryl ynones (Scheme 1b). 11…”