oa Harnessing the Unique Properties of Iridium

With the exception of osmium, iridium is the least abundant of the six platinum group metals. It is of crucial importance in a number of high technology applications and, at least in the past, has been regarded as a strategic material and stockpiled by major governments. In recent years it has become more readily available, prompting renewed interest by researchers, including those seeking to develop improved catalysts. In this paper we discuss the results of our investigations on the use of iridium as an hydrogenation catalyst. Data are presented on the characteristics of an iridium-based catalyst developed here for the effective and selective synthesis of substituted N-aryl-hydroxylamines and chloro-substituted anilines, symmetric and asymmetric azoxybenzenes, and unsaturated alcohols. These demonstrate that iridium is unique among the platinum metals.