Organoselenium-Catalyzed Aza-Wacker Reactions: Efficient Access to Isoquinolinium Imides and an Isoquinoline N-Oxide

Abstract

An efficient approach for the organoselenium-catalyzed aza-Wacker reaction of olefinic hydrazones and an oxime to form isoquinolinium imides and an isoquinoline N-oxide is developed. This transformation involves a direct intramolecular C–H amination using hydrazones and an oxime as imine-type nitrogen sources. This work not only provides a new approach for the construction of isoquinoline derivatives, but also expands the scope of nitrogen sources in electrophilic selenium catalysis.

Comprehensive Strategies for the Synthesis of Isoquinolines: Progress Since 2008

“…Under these reaction conditions various functional groups and sustained and delivered isoquinolinium imides 560 is good to excellent yields (Scheme 324). [323] Authors have proposed a plausible mechanism based on the previous reports. [324] In the first step, diphenyl diselenide is getting oxidized to PhSeX, Next, selenium ion addition across the double bond takes place to leave seleniranium intermediate A.…”

“…Under these reaction conditions various functional groups and sustained and delivered isoquinolinium imides 560 is good to excellent yields (Scheme 324). [323] …”

Cluster Preface: Organosulfur and Organoselenium Compounds in Catalysis

“…4 Diphenyl diselenide could also be oxidized by NFSI to generate phenylselenyl fluoride in situ, which effectively catalyzed aza-Wacker reactions of olefinic hydrazones and oximes to give isoquinolinium imides and an isoquinoline N-oxide, respectively (X. Zhao). 5 Other than small molecules, the synthesis of polyanilines through the organoselenium-catalyzed oxidation of anilines is reported (L. Yu and Q. Xu). 6 Compared to Lewis base catalysis, using organochalcogens as acid catalysts (-acids and -hole catalysts) are less studied.…”

Recent advances in selenium promoted or catalyzed electrophilic aminations of alkenes and alkynes

“…Analogously, isoquinoline derivatives were accessible from ortho-styryl substituted benzaldehyde hydrazones or oximes. 104 Scheme 34 shows a representative example. The formed isoquinolinium imide has been reduced with NaBH4or converted into a fused pyrazoloisoquinoline by a 1,3-dipolar cyclo addition reaction with 4-ethynylanisole.…”