Aerobic C–H Functionalization Using Pyrenedione as the Photocatalyst

Abstract

We disclose a visible-light-promoted aerobic alkylation of activated C(sp3)–H bonds using pyrenedione (PYD) as the photocatalyst. Direct C–H bond alkylation of tetrahydrofuran with alkylidenemalononitriles is accomplished in over 90% yield in the presence of 5 mol% of PYD and 18 W blue LED light under ambient conditions. The substrate scope is extended to ethers, thioethers, and allylic C–H bonds in reactions with various electrophilic Michael acceptors. The catalytic turnover process is facilitated by oxygen. Our work represents the first example of using PYD as a photocatalyst to promote C(sp3)–H alkylation, revealing the unique character of PYD as a novel organophotocatalyst.

Sequential Modifications of Metal–Organic Layer Nodes for Highly Efficient Photocatalyzed Hydrogen Atom Transfer

“…Zr-OTf-AQ MOL showed lower activity and afforded 3a in 30% yield (Figure a, entry 5). Additionally, in the cross-coupling between THF and 2a , Zr-OTf-EY exhibited orders of magnitude higher TONs than other commonly used HAT catalysts, including 9-fluorenone (FLN), thioxanthone (TXO), and tetrabutylammonium decatungstate (TBADT) with TONs of 3.6, 4.6, and 45, respectively (Figure b). − Time-dependent experiments were also performed for coupling reactions between THF and 2a , using 0.05 mol % Zr-OTf-EY or 0.05 mol % EY and 0.5 mol % Zr-BTB-OTf as catalysts under identical conditions (Figure c). Zr-OTf-EY catalyzed the reaction about three times faster than the homogeneous control.…”