Rhodium‐Catalyzed Homogeneous and Aqueous Biphasic Hydroformylation of the Acrolein Acetal 2‐Vinyl‐5‐Methyl‐1,3‐Dioxane

Abstract

International audienceThe rhodium-catalyzed hydroformylation of 2-vinyl-5-methyl-1,3-dioxane (VMD), the acetal derived from acrolein and 2-methyl-1,3-propanediol, has been investigated. Under homogeneous conditions, phosphane-based catalysts afforded perfect chemoselectivity for the aldehydes. Catalysts based on diphosphine ligands with a narrow bite angle of approximately 85°, such as 1,2-bis(phenylphosphino)ethane, were found to favor the branched aldehyde 2, with selectivities of up to 78 %, whereas diphosphine ligands with a large bite angle of approximately 110°, such as xantphos, produce the linear aldehyde 1 with up to 91 % selectivity. Control of the 1/2 regioselectivity by means of the P[BOND]Rh[BOND]P bite angle was ascertained with a variety of ethylene-, hydrazino- and CNC-bridged diphosphines, irrespective of electronic factors induced by these ligands. Under aqueous biphasic conditions, chemoselective hydroformylation of VMD proved feasible only with disulfonated xantphos; in this case, remarkable activities (turnover frequencies of up to 1075 molaldehyde molRh−1 h−1 at 120 °C) were observed, with up to 82 % yield for the linear aldehyde. On the other hand, the catalyst based on tetrasulfonated dppe systematically induced the formation of very large amounts of the hydrogenated product

Branched-Selective Hydroformylation of Nonactivated Olefins Using an N-Triphos/Rh Catalyst

“…After subjecting the precatalytic 1:2 mixture of [Rh(acac)(CO) 2 ] and azatriphos 1a to the catalytic conditions ([Rh] = 5 mM, [1a] = 10 mM, CO/ H 2 (1:1) = 2.0 MPa, 100 °C, 0.5 h), the major species detected after removal of the solvent and any volatiles was the bis-ligated monohydride complex [RhH(κ 2 -1a) 2 ] (4) by 31 P{ 1 H} NMR (δ P : 15.4 (d, 1 J PRh = 141.0 Hz, 4P), −30.9 (s, 2P)) (Scheme 3). This was confirmed to be the correct assignment by a separate synthesis (see Supporting Information), and in solution it is probably tetrahedral with the hydride jumping from face to face, as evidenced from broadening of the hydride signal by 1 H NMR spectroscopy (Figure S46) as well as broadening of the coordinated phosphorus signals by 31 P{ 1 H} NMR spectroscopy at −50 °C (Figure S49). 27 When complex 4 was used as the catalyst under otherwise identical conditions (Table 2, entries 9 and 10), the same reactivity and selectivity were observed as the in situ generated catalyst, confirming that this complex is at least a competent precatalytic species.…”

Cross‐metathesis of fatty acid methyl esters with acrolein: An entry to a variety of bifunctional compounds

“…Acrolein was purchased from Sigma‐Aldrich and stored under inert atmosphere at +4°C. Acetal 12 (mixture of trans (M) and cis (m) isomers) was generously supplied by J. Ternel . The reactions were monitored using a Shimadzu 2014 gas chromatograph equipped with an Equity TM –1 Fused Silica capillary column (30 m × 0.25 mm × 0.25 µm) and a FID detector.…”

The Pivotal Role of Catalysis in France: Selected Examples of Recent Advances and Future Prospects.

“…In EuroBioref, catalytic technologies were at the core of the project and hereafter some examples of its developments are cited: catalysts were developed for the synthesis of nitriles from fatty acids or esters; for conversion of fatty unsaturated compounds through variations of metathesis reactions . Tandem isomerization/hydroformylation was used for the production of polyamide‐12 precursor from bio‐sourced 10‐undecenenitrile; acetal synthesis was further envisioned through a conventional approach and through reactive distillation or simulated moving bed membrane reactor (SMBR) to overcome chemical equilibriums; glycerol was valorized to various compounds including acrylonitrile, or hydroxymethyl‐ 2 ‐oxazolidinones; glycerol‐derived products were hydroformylated; Guerbet reaction was used to yield various alcohols with applications as aviation fuels; 1 ‐butanol direct conversion to maleic anhydride was developed to be implemented in an original phthalic anhydride ( exo ‐xylene) co‐production configuration; syngas conversion technologies were improved to yield alcohols, as well as methylmercaptan, taking advantage of the presence of H 2 S in black liquor‐derived syngas. In Biocore, chemocatalysis was used to convert C6 cellulose pulp into isosorbide .…”