Iron catalyzed cross coupling reactions of aromatic compounds
申请人:——
公开号:US20030220498A1
公开(公告)日:2003-11-27
A process for the production of compounds Ar—R
1
by means of a cross-coupling reaction of an organometallic reagent R
1
—M with an aromatic or heteroaromatic substrate Ar—X catalyzed by one or several iron salts or iron complexes as catalysts or pre-catalysts, present homogeneously or heterogeneously in the reaction mixture. This new invention exhibits substantial advantages over established cross coupling methodology using palladium- or nickel complexes as the catalysts. Most notable aspects are the fact that (i) expensive and/or toxic nobel metal catalysts are replaced by cheap, stable, commercially available and toxicologically benign iron salts or iron complexes as the catalysts or pre-catalysts, (ii) commercially attractive aryl chlorides as well as various aryl sulfonates can be used as starting materials, (iii) the reaction can be performed under “ligand-free” conditons, and (iv) the reaction times are usually very short.
and -CF(3) groups are compatible. The method also allows for consecutive cross-coupling processes in one pot, as exemplified by the efficient preparation of compound 12, and has been applied to the first synthesis of the cytotoxic marine natural product montipyridine 8. In contrast to the clean reaction of (hetero)aryl chlorides, the corresponding bromides and iodides are prone to a reduction of their