Organocatalytic Enantioselective Friedel–Crafts Reaction of 1‐Naphthols with Isatins and an Unexpected Spontaneous Dehydration Process

Abstract

in Chinese:Asian

Amine‐Catalyzed Highly Regioselective and Stereoselective C(sp2)–C(sp2) Cross‐Coupling of Naphthols with trans‐α,β‐Unsaturated Aldehydes

“…In this context, naphthols have been demonstrated to be effective electron‐rich species in Friedel–Crafts (F–C) type reactions with a range of electrophiles, such as azodicarboxilates, ketones, aldimines, and ketimines, and activated olefins have also been realized (Scheme ) and phenol “O” involved conjugate addition processes by organocatalysis . In our own effort, we have reported the F–C reactions of 1‐naphthols with aldimines and isatins . It is recognized that these reactions generally proceed dominantly at the ortho ‐position of 1‐naphthols, indicating this position is much more active than the para ‐position (Scheme a) .…”

Recent Advances in Catalytic Asymmetric Synthesis of Tertiary Alcohols via Nucleophilic Addition to Ketones

“…In 2014, the groups of Wang and Chimni independently reported an asymmetric Friedel–Crafts reaction of isatins with 1‐naphthols 125 using bifunctional tertiary‐amine thiourea catalysis (Scheme ). Wang and co‐workers employed 10 mol% of the quinidine‐derived thiourea 126a as catalyst to promote this reaction.…”

Organocatalyzed Asymmetric Friedel‐Crafts Reactions: An Update

“…An organocatalytic asymmetric AF‐CA reaction of isatins and 1‐naphthols was reported by using bifunctional thiourea‐tertiary amine as efficient organocatalysts in 2014 . A number of isatin derivatives reacted well with 1‐naphthols under Cinchona obtained thiourea 152 to give chiral 3‐aryl‐3‐hydroxy‐2‐oxindoles 153 a – y containing significant biological activity with satisfactory to good ee value (37–83 %) and good yield (70–84 %).…”

“…A suggested mechanism is shown in Figure , in which enantioinduction can be accomplished in the AF‐CA addition of isatins and 1‐naphthols via synergistic activation via bifunctional thiourea‐tertiary amine organocatalysts. Remarkably, it was demonstrated that the epi CDT mediated the AF‐CA transformation of 1‐naphthols to isatins …”