Chiral phosphoric acid-catalyzed enantioselective aza-Friedel–Crafts reaction of naphthols and electron-rich phenols with 2-aryl-3H-indol-3-ones

Abstract

The enantioselective aza-Friedel–Crafts reaction is one of the most straightforward and efficient strategies for constructing a new carbon-carbon bond bearing quaternary stereocenter in organic synthesis, but the catalytic asymmetric aza-...

Csp2–H functionalization of phenols: an effective access route to valuable materials via Csp2–C bond formation

“…Phosphorus-based acids are common acids used in organic synthesis, and the organic derivatives are commonly applied as an organocatalytic system. 80–84 Inorganic acids, such as H 3 PO 3 and H 3 PO 4 , have been less used: however, they turned out to be extremely efficient in the alkylation of phenols and naphthols with alkenes in Friedel–Crafts-type alkylation (Scheme 26 and 27). Zhou's research group reported the use of phosphorus in the synthesis of 39 examples of alkylated phenols with isolated yields ranging from 31% to 96%.…”

“…These advantages can be attributed to two H-bonds and π–π interactions enabled by the chiral phosphoric acid ( Scheme 48 ). 82 …”

Organocatalyst‐Controlled Divergent Asymmetric Aza‐Friedel‐Crafts Reactions of Indol‐3‐ones with 1‐ and 2‐Naphthols

“…To further extend the scope of these privileged class of compounds, we herein describe the asymmetric aza-Friedel-Crafts-type reaction of indol-3-ones with naphthols (Scheme 1b). Both 1-and 2naphthols are viable reaction substrates, [12] delivering the chiral 2,2-diaryl indolin-3-ones (4) and tetrahydrofuroindole (7) compounds, respectively, both of which contains the quaternary stereogenic centres. These two structurally distinct chiral indolinone-derived compounds would find potential utility in natural product synthesis and medicinal chemistry.…”

B(C6F5)3‐Catalyzed Aza‐Friedel–Crafts Reaction of Indolizines with 2‐Aryl‐3H‐indol‐3‐ones

“…[11] Therefore, a myriad of protocols has been developed for the construction of indolin-3-one derivatives. [12] Inspired by our previous works, [13] herein we developed the catalytic C(sp 2 )À H transformations of indolizines with 2-aryl-3H-indol-3-ones in the presence of B(C 6 F 5 ) 3 -based catalyst towards various indolizine -based C2-quaternary indolin-3-ones with high yields and regioselectivities (Scheme 1b).…”