Benign Catalysis with Iron: Unique Selectivity in Catalytic Isomerization Reactions of Olefins

Abstract

The use of noble metal catalysts in homogeneous catalysis has been well established. Due to their price and limited availability, there is growing interest in the substitution of such precious metal complexes with readily available and bio-relevant catalysts. In particular, iron is a "rising star" in catalysis. Herein, we present a general and selective iron-catalyzed monoisomerization of olefins, which allows for the selective generation of 2-olefins. Typically, common metal complexes give mixtures of various internal olefins. Both bulk-scale terminal olefins and functionalized terminal olefins give the corresponding products under mild conditions in good to excellent yields. The proposed reaction mechanism was elucidated by in situ NMR studies and supported by DFT calculations and extended X-ray absorption fine structure (EXAFS) measurements.

Diferrate [Fe2(CO)6(μ‐CO){μ‐P(aryl)2}]− as Self‐Assembling Iron/Phosphor‐Based Catalyst for the Hydrogen Evolution Reaction in Photocatalytic Proton Reduction—Spectroscopic Insights

“…The parameters obtained for 3CO in THF/TEA/H 2 O( 4:1:1) solution agree very wellw ith previous EXAFS studies. [38] The Fe-Fe coordination number deviates slightly from the expected number of two, which is in line with the presence of iron species of lower nuclearity.N onetheless,t he bond distances agree very wellwith the crystal structure data of 3CO. [39] By adding one equivalent of P(d) 3 ,acharacteristicF e-P shell appearsw ith ac oordination number of 0.4.…”

Alkene Isomerisation Catalysed by a Ruthenium PNN Pincer Complex

“…[38,39] Recently, researchers have focused on the selectivity of the alkene isomerisation. Beller and Grotjahn have developed catalysts which allow a selective one-position shift of the double bond with high selectivity for E isomers, [27,40] whereas other groups focused on the synthesis of the less thermodynamically favoured Z isomers. [41] Two different mechanisms are generally believed to be operative for alkene isomerisation.…”

“…[12] Other examples are the isomerisation of allyl benzenes such as estragol or safrole, which are of great interest for the fragrance industry. [13,14] A wide range of isomerisation catalysts have been developed based on various metals such as Pd, [15][16][17] Ru, [18][19][20][21][22] Ti, [23][24][25] V, [26] Fe, [27][28][29] Rh, [30][31][32] Mo, [33] Ni, [34][35][36] etc., but also metal-free systems such as frustrated Lewis pairs. [37] One of the most active catalysts is the ruthenium-based "alkene zipper" developed by Grotjahn and co-workers.…”

Application of quantum calculations in the chemical industry—An overview

“…The same reaction is also the topic of a recent experimental and computational paper by Beller and scientists from Evonik that focuses on catalysts prepared from Fe(CO) 5 , KOH, and H 2 O (computational models: trinuclear anionic carbonyl hydrido complexes) . The remarkable selectivity of this catalyst for 2‐olefin products is rationalized by the necessity of breaking up an agostic metal–alkyl interaction, which is computed to occur most easily for terminal methyl groups.…”