Homogeneous catalysis iron-based catalyst

CO and two of H2O and produces two moles of CO2. Homogeneous catalysis of this reaction can be accomplished with an iron carbonyl in conjunction with a Bronsted acid or base. Thus it appears that conditions might be found where the shift reaction itself can be eflFected homogeneously using metal complex catalysts. To this end, we have been examining the activity of various homogeneous catalysts for the shift reaction, and our investigations of metal carbonyl cluster complexes are summarized here. 

It is difficult to summarize all the progress of the homogeneous catalytic aldol reaction due to the space limitations. With representative or selected examples, this article focuses on those efforts in homogeneous catalysis and will be discussed with selected examples according to the different types of catalysts il) transition metals based Lewis acids, such as palladium, copper, iron, etc (2)... 

The first application of a phosphinine-based catalyst in homogeneous catalysis was reported in 1996 by Zenneck et al. The f/ -phosphinine-iron complex 33 was used in the catalytic [2 -h 2 -h 2] cyclotrimerization of the electron-poor alkyne dimethyl acetylenedicarboxylate to give C6(C02Me)6 and in the co-cyclotrimer-ization of methyl propargylether with butyronitrile affording functionalized pyridine derivatives (Scheme 6.8) [60]. Turnover-numbers of up to 160 for the pyridine derivatives and chemoselectivities of up to 1.4 1 (pyridinesiarenes) were observed. Nevertheless, the efficiency of 33 is significantly lower compared to classical CpCo catalysts [61, 62]. 

---