Selective hydroformylation-hydrogenation tandem reaction of isoprene to 3-methylpentanal

Abstract

The hydroformylation of isoprene catalysed by rhodium phosphine complexes usually yields a broad mixture of the monoaldehydes, the isomeric methylpentenals, as well as the dialdehyde 3-methyl-1,6-hexandial. Under usual reaction conditions the products of a consecutive hydrogenation are only formed as minor by-products. Surprisingly we discovered now a selective auto-tandem reaction consisting of a hydroformylation and a hydrogenation step if a rhodium complex with the chelate ligand bis(diphenylphosphino)ethane is used as catalyst. If branched aromatic solvents like cumene are applied the conversion of isoprene is nearly quantitatively and the yield of the tandem product 3-methylpentanal amounts to 85%.

Tandem hydroformylation/isomerization/hydrogenation of bio-derived 1-arylbutadienes for the regioselective synthesis of branched aldehydes

“…The hydroformylation of 1,3-butadiene, isoprene and piperylene is useful for the synthesis of commodity products. [14][15][16][17][18] Also, 1,3-dienes moieties often occur in natural products, and their hydroformylation leads to aldehydes of interest for the fragrance industry. [19][20][21] However, hydroformylation of this kind of substrates is particularly difficult to achieve.…”

Homogeneously Catalyzed 1,3‐Diene Functionalization – A Success Story from Laboratory to Miniplant Scale

“…However, the hydroformylation of isoprene allows access to saturated C6 aldehydes in one tandem catalytic step. It consists of the initial hydroformylation and subsequent hydrogenation of the remaining double bond . A successful reaction sequence was carried out using a Rh/diphenylphosphinoethane (DPPE) system and yields of up to 85 % can be achieved (Figure , upper reaction).…”

“…It consists of the initial hydroformylation and subsequent hydrogenation of the remaining double bond. [71] A successful reaction sequence was carried out using a Rh/diphenylphosphinoethane (DPPE) system and yields of up to 85 % can be achieved ( Figure 28, upper reaction). Rhodiumcatalyzed hydroaminomethylation is also possible with isoprene utilizing the hydroformylation/hydrogenation activity.…”

Nanotubular TiO2-supported amorphous Co–B catalysts and their catalytic performances for hydroformylation of cyclohexene

“…Several million tons of aldehydes are produced annually by the reaction [1]. For decades, the Co-based [2,3], Ir-based [4,5] and Rh-based [6] catalysts for hydroformylation are widely investigated.…”