Iron-Catalyzed Synthesis of Pyrrolo[2,1-a]isoquinolines via 1,3-Dipolar Cycloaddition/Elimination/Aromatization Cascade and Modifications

Abstract

We have developed an iron-catalyzed synthesis of pyrrolo[2,1-a]isoquinoline derivatives with tetrahydroisoquinolines, arylacyl bromides and nitroolefins. Highly functionalized pyrrolo[2,1-a]isoquinolines can be obtained in moderate to good yields through a three-component N-alkylation/oxidative 1,3-dipolar cycloaddition/elimination/aromatization cascade. The obtained products in this study can be easily modified by easy chemical transformations to structurally complex molecules bearing privileged framework.

Nitration of Pyrrolo[2,1-a]isoquinolines

“…Iron­(III) nitrate nonahydrate (AR, 99.9% purity), ammonium ceric nitrate (AR, 99% purity), and copper nitrate hydrate (AR, 99% purity) were purchased from Shanghai Macklin Biochemical Technology Co., Ltd. Compounds 1 and 3 were prepared following our reported procedures. , All compounds 1 and 3 were known compounds except for compound 1f .…”

TBHP/Et3N-Promoted Chemoselective Formylation and Peroxidation of Pyrrolo[2,1-a]isoquinolines

“…All of the reagents and solvents were obtained from commercial sources and used without further purification. Compounds 1 and 4a – b were prepared following our reported procedures . TBHP ( tert -butyl hydroperoxide solution, 70% in H 2 O) was purchased from Shanghai Macklin Biochemical Technology Co., Ltd. All compounds 1 and 4 were known compounds.…”

AcBr/DMSO Mediated Sulfenylation of Pyrrolo[2,1-a]isoquinolines

“…DCM and DMSO (AR) were dried with 4 Å MS before use. Compounds 1 and 5a – 5d were prepared following the reported procedures. , All substrates 1 and 5a – d are known compounds.…”