0

Microwave-assisted Cyclizations Promoted by Polyphosphoric Acid Esters: A General Method for 1-aryl-2-iminoazacycloalkanes

Jimena E Díaz, María C Mollo, Liliana R Orelli

Beilstein J Org Chem. 2016 Sep 14;12:2026-2031.

PMID: 27829907

Abstract:

The first general procedure for the synthesis of 5 to 7-membered 1-aryl-2-iminoazacycloalkanes is presented, by microwave-assisted ring closure of ω-arylaminonitriles promoted by polyphosphoric acid (PPA) esters. 1-Aryl-2-iminopyrrolidines were easily prepared from the acyclic precursors employing a chloroformic solution of ethyl polyphosphate (PPE). The use of trimethylsilyl polyphosphate (PPSE) in solvent-free conditions allowed for the synthesis of 1-aryl-2-iminopiperidines and hitherto unreported 1-aryl-2-iminoazepanes. The cyclization reaction involves good to high yields and short reaction times, and represents a novel application of PPA esters in heterocyclic synthesis.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP40623469 Trimethylsilyl polyphosphate Trimethylsilyl polyphosphate 40623-46-9 Price
qrcode