Synthesis of Industrial Primary Diamines via Intermediate Diols – Combining Hydroformylation, Hydrogenation and Amination

Abstract

A homogenous transition metal catalysis that combines hydroformylation, hydrogenation and direct amination presents an elegant multi-step pathway for synthesising primary diamines from olefins and ammonia. The valuable intermediate TCDdiamine is obtained, which has a wide range of industrial applications as a monomer building block. The rhodiumcatalysed hydrohydroxymethylation step converts non-conjugated dienes to the intermediate diols. Ammonia is added in a second ruthenium-catalysed amination step to obtain primary diamines. The conditions for both reactions were first optimised independently and combined to design a tandem reaction. For the amination reaction of the diol, excellent diamine yields of up to 88 % in toluene were achieved. An analysis of the interactions between the two catalytic systems demonstrated that the conditions of both single reaction steps counteract each other, meaning the presence of either rhodium or ruthenium blocks the other respective reaction. Using a twostep approach, optimised reaction conditions were applied to achieve equally high diamine yields of 88 %.

Auto-tandem catalytic reductive hydroformylation with continuous multiphase catalyst recycling

“…16,17 Rhodium is the most active metal in hydroformylation reactions; hence, most recent investigations focus on rhodium-based systems, typically in combination with tertiary alkylamines. 18–25 In a recent publication from our group, the role and necessary properties of amines in reductive hydroformylation were characterized. 26…”

Auto-Tandem Catalytic Reductive Hydroformylation in a CO2-Switchable Solvent System

“…To avoid reductive amination reactions, , only tertiary amines are applicable in reductive hydroformylation. Furthermore, the tertiary alkylamines used in previous studies show poor performance in CO 2 capture and therefore are not suitable for designing a switchable solvent system.…”

“…However, auto-tandem catalysisusing the same catalyst for both reaction steps under the same conditionsrepresents the most efficient variant . Auto-tandem reductive hydroformylation was first described for cobalt-based catalysts, although they achieve poor selectivity and require harsh conditions. , Recent investigations usually focus on rhodium catalysts due to their superior activity in hydroformylation, which are capable of auto-tandem reductive hydroformylation, e.g., in combination with tertiary alkylamines. − Necessary steric and electronic properties of amines in reductive hydroformylation were previously published by our group. , …”

REDIFUEL: Robust and efficient processes and technologies for drop-in renewable fuels for road transport

“…A one-step approach, in which both reactions (hydroformylation and subsequent hydrogenation) take place in one reaction vessel (Figure 2, left). Alternatively, separate reactors and dedicated reaction conditions and catalysts can be applied for each reaction step [Torres, G. M. et al 2015;Fuchs, S. et al 2018].…”