Syntheses of Stereochemically Diverse Nine-Membered Ring-Containing Biaryls
作者:Shyam Krishnan、Stuart L. Schreiber
DOI:10.1021/ol048273c
日期:2004.10.1
A library of nine-membered, biaryl-containing rings has been synthesized in parallel on polystyrene macrobeads. Dimeric medium rings were shown to be accessible via a regio- and stereoselective double cyclization.
Synthesis of Medium Ring Nitrogen Heterocycles via a Tandem Copper-Catalyzed C−N Bond Formation−Ring-Expansion Process
作者:Artis Klapars、Sean Parris、Kevin W. Anderson、Stephen L. Buchwald
DOI:10.1021/ja038565t
日期:2004.3.1
A simple method for the preparation of medium ring heterocycles (7-, 8-, 9-, and 10-membered) has been developed. The process employs a Cu-catalyzed coupling of beta-Iactam with an aryl bromide or iodide followed by intramolecular attack of a pendant amino group. In some instances, the intermediate beta-lactam is observable but can be converted to the aza-heterocycle by catalysis. Acetic acid was found to be superior to transition metal complexes as a catalyst for this ring-expansion process.