A Synthetic Route to Tetrahydro-1<i>H</i>-azepino[4,3,2-<i>cd</i>]indoles via Ring-Opening Cyclization of Activated Azetidines with 4-Bromoindole: Toward a Vasopressin V2 Receptor Antagonist
Gaurav Goswami, Bharat Singh, Imtiyaz Ahmad Wani, Abhijit Mal, Manas K. Ghorai
Abstract
A simple one-pot, two-step strategy for the synthesis of tetrahydro-1 H -azepino[4,3,2- cd ]indoles via Lewis acid-catalyzed S N 2-type ring opening of activated azetidines with 4-bromoindole, followed by a Pd-catalyzed intramolecular C–N cyclization reaction, with good to excellent yields is described. Utilizing this protocol, the vasopressin V2 receptor antagonist precursor has been synthesized easily. Enantioenriched tetrahydro-1 H -azepino[4,3,2- cd ]indoles were obtained by starting from enantiopure azetidine.
Topics & Concepts
Ring (chemistry)Combinatorial chemistryVasopressinSimple (philosophy)ChemistryStereochemistryComputer scienceOrganic chemistryInternal medicineMedicineEpistemologyPhilosophySynthesis and Catalytic ReactionsAsymmetric Synthesis and CatalysisPhenothiazines and Benzothiazines Synthesis and Activities