Tom Gaide

Renewable Surfactants through the Hydroaminomethylation of Terpenes

A catalytic system was developed to enable the use of industrially available terpenes (e.g., β‐myrcene, β‐farnesene) in hydroaminomethylation to obtain renewable building blocks for surfactants in two steps. This homogeneously catalyzed tandem reaction includes both hydroformylation and enamine condensation steps, followed by hydrogenation. Under the optimized conditions, the Rh/1,2‐bis(diphenylphosphino)ethane catalytic system delivers products in high yields (70 %) after short reaction times (3 h) with unprecedentedly high turnover frequency (TOF) values for the hydroformylation of 1,3‐dienes of over 739 mol mol−1 h−1. This is the highest TOF reported to date for the hydroformylation of a 1,3‐diene. Furthermore, regioselectivities of 97 % and above were observed in the hydroformylation step, which is extraordinarily high for the conversion of 1,3‐dienes. The terpene‐derived amines obtained were further functionalized to quaternary ammonium compounds that were found to show surface activity quite similar to that of industrially available quaternary ammonium compounds. The hydroaminomethylation of terpenes achieves higher step efficiency than industrial means and makes use of an alternative, renewable feedstock to synthesize more environmentally friendly surfactants.

Tandem Reductive Hydroformylation of Castor Oil Derived Substrates and Catalyst Recycling by Selective Product Crystallisation

An orthogonal tandem catalytic system consisting of rhodium and ruthenium complexes yielded linear C12 α,ω‐bifunctional compounds from commercial, castor oil derived renewable substrates. With aldehyde yields up to 88 % and selectivities to the linear species of up to 95 %, this approach is direct and atom economic and provides easy access to potential polymer precursors for polycondensates. Additionally, a straightforward method for selective product crystallization was developed, which enabled recycling of the tandem catalytic system for two runs with excellent activity and simultaneously provided a high‐purity product.

Hydroformylation of Renewables

The formal addition of a hydrogen atom and a formyl group to a double bond in the presence of a transition metal catalyst is called hydroformylation or oxo-synthesis. This reaction, discovered by Otto Roelen in 1938 during his investigations about the Fischer–Tropsch reaction, is one of the most important industrial applications of homogeneous catalysis [1].