Rhodium/bisphosphite catalytic system for hydroformylation of styrene and its derivatives

Abstract

Different kinds of mono-and bidentate phosphite ligands were used in Rh-catalyzed hydroformylation of styrene to illustrate the influence of steric and electronic properties of ligands on catalytic performance. High activity (99.9%) and good regioselectivity (85.4%) to the linear aldehyde were achieved under optimum conditions in the presence of Rh/bisphosphite complex (bisphosphite: 2,2 0 -bis(dipyrrolylphosphinooxy)-1,1 0 -(AE)-binaphthyl). This system makes it possible to prepare functionalized terminal aldehydes from readily available styrene or its derivatives through hydroformylation with high linear selectivity.

Practical Synthesis of (Z)-α,β-Unsaturated Nitriles via a One-Pot Sequential Hydroformylation/Knoevenagel Reaction

“…In the case of styrene, under the standard conditions, the molar ratio of the linear/branched (l/b) product is 2/1 and the total yield was 78%. The l/b ratio could be increased to 4/1 maintaining the same yield by using sterically demanding L4 since the steric hindrance around the Rh center would inhibit the formation of the benzylic Rh species, which would tend to produce branched aldehydes . In the presence of tri­(1 H -pyrrol-1-yl)­phosphane, the reaction of prop-1-en-2-ylbenzene with 2-phenylacetonitrile afforded c34 in moderate yield because its reactivity was much lower than styrene.…”

2‐Arylpropylamines from 1‐Propenylbenzenes in a New One‐Pot Metathesis–Hydroaminomethylation Protocol

“…For the hydroformylation of styrenes, lower temperatures were reported to favor the formation of branched aldehydes. [53,58,59] It has been suggested that at higher temperatures the migration of the hydride to the double bond in the rhodium-styrene intermediate π-complex becomes reversible making it easier the conversion of branched rhodium-alkyl organometallic intermediates to the linear ones. [60] A similar temperature effect was observed in this study: the iso/n ratio in the final amine 8 ai was 88/12 at 80 °C, whereas only 78/22 at 120 °C (Table 4, runs 2, 4 and 5).…”

Hydroformylation of 2,5‐norbornadiene in organic/aqueous two‐phase system and acceleration by cationic surfactants

“…Recently, much attention has been concentrated on the hydroformylation of special olefins because of its high added value in the manufacture of fine chemicals . Thus, the hydroformylation of 2,5‐norbornadiene (NBD) is of interest, since the carboxylated derivatives of its dialdehyde products are applied in the manufacture of advanced photoelectron instruments .…”