Formation of a Tetracyclic Isoquinoline Derivative by Rearrangement of a [(Bromophenyl)butyryl]oxazolidinone

Abstract

Treatment of 3‐[4‐(2‐bromophenyl)‐2‐phenylbutyryl]‐4,4‐dimethyloxazolidin‐2‐one with LDA in THF launched a domino rearrangement sequence ending in the assembly of a tetracyclic cyclopentaoxazolo[3,2‐b]isoquinolin‐6‐one derivative. Two mechanisms involving an SRN1‐type process were proposed. EPR spectroscopic and 13C‐labelling experiments suggested that both were operative.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Iterative double cyclization reaction by SRN1 mechanism. A theoretical interpretation of the regiochemical outcome of diazaheterocycles

“…15 An S RN 1 synthetic strategy to obtain heterocyclic compounds was previously developed based on the intramolecular cyclization of substrates bearing both the leaving group and the nucleophilic center. 16 This methodology has been recently applied to the synthesis of 1-phenyl-1-oxazolinoindan derivatives and their related compounds; 17 tetracyclic isoquinoline derivatives; 18 a series of substituted 9H-carbazoles and carbolines; [19][20][21] aporphine and homoaporphine alkaloids; 22 pyrroles, indoles, and pyrazoles; 23 indazoles; 24 pyridio[1,2-a]benzimidazoles; 25 2-pyrrolyl and 2-indolyl benzoxazoles, 26,27 among others. Moreover, an intermolecular S RN 1 reaction of substituted iodobenzylamines with several tetralones afforded a series of benzo[c]phenanthridines with modest overall yields aer several steps.…”

Aromatic and Heteroaromatic Substitution by S RN 1 and S N 1 Reactions

“…The initial steps involve a ring closure reaction to form efficiently a quaternary center (Scheme 10.41) [57]. Under these conditions, a new fused tetracyclic cyclopentaoxazoloisoquinolinone system 19 is assembled in a multistage rearrangement.…”

Photoinduced Synthesis of Dibenzofurans: Intramolecular and Intermolecular Comparative Methodologies

“…The S RN 1 mechanism has clearly manifested to be useful for obtaining heterocyclic compounds . Recently, the S RN 1 reaction was applied to form new C–C bonds in the synthesis of heterocycles such as phenanthridines and benzophenanthridines, phenanthrolines, 1-phenyl-1-oxazolyl-Indane derivatives, cyclopenta-oxazolo-isoquinolin-6-ones carbazoles and carbolines, , pyrrole, indole, and pyrazole fused azaheterocycles . The formation of C-heteroatom bonds is also reported as a consequence of an intramolecular cyclization to generate compounds such as 9 H -carbazoles, among others.…”