13050-14-1Relevant articles and documents
Rhodium versus iridium catalysts in the controlled tandem hydroformylation-isomerization of functionalized unsaturated fatty substrates
Ternel, Jrmy,Couturier, Jean-Luc,Dubois, Jean-Luc,Carpentier, Jean-Franois
, p. 513 - 520 (2015)
The hydroformylation of 10-undecenitrile (1) and related unsaturated fatty substrates (H2C=CH(CH2)7CH2R; R=CO2Me, CH2Br, CHO) has been studied with rhodium, iridium, ruthenium, and palladium biphephos catalysts. The reactions proceeded effectively with all four systems, with high selectivities for the linear aldehyde (ratio of linear/branched aldehydes=99:1). The biphephos-bis[chloro(cyclooctadiene)iridium] system showed a non-optimized hydroformylation turnover frequency (TOFHF) of 770h-1 that was only approximately 5times lower than that of the rhodium-based system (TOFHF=3320h-1); the palladium and ruthenium biphephos systems were less active (TOFHF=210 and 310h-1, respectively). Upon recycling, remarkable productivities were achieved in both cases (TON≈58-000mol(1/1-int)-mol(Ir)-1 and 250-000mol(1/1-int)-mol(Rh)-1, in which int=internal olefin). Competitive isomerization of terminal to internal olefins occurred with these catalysts. Iridium biphephos systems allowed slightly better control of the distribution of the internal isomers than the rhodium biphephos catalyst, with higher ratios of 9-/8-undecenitrile (1-int). Place your bets now: Iridium-biphephos catalysts are highly effective in the controlled tandem isomerization-hydroformylation of 10-undecenitrile and related functionalized unsaturated fatty substrates.
Rhodium-catalyzed tandem isomerization/hydroformylation of the bio-sourced 10-undecenenitrile: Selective and productive catalysts for production of polyamide-12 precursor
Ternel, Jeremy,Couturier, Jean-Luc,Dubois, Jean-Luc,Carpentier, Jean-Francois
, p. 3191 - 3204 (2013/12/04)
The hydroformylation of 10-undecenenitrile (1) - a substrate readily prepared from renewable castor oil - in the presence of rhodium-phosphane catalysts systems is reported. The corresponding linear aldehyde (2) can be prepared in high yields and regioselectivities with a (dicarbonyl)rhodium acetoacetonate-biphephos [Rh(acac)(CO)2-biphephos] catalyst. The hydroformylation process is accompanied by isomerization of 1 into internal isomers of undecenenitrile (1-int); yet, it is shown that the Rh-biphephos catalyst effectively isomerizes back 1-int into 1, eventually allowing high conversions of 1/1-int into 2. Recycling of the catalyst by vacuum distillation under a controlled atmosphere was demonstrated over 4-5 runs, leading to high productivities up to 230,000 mol (2)×mol (Rh)-1 and 5,750 mol (2)×mol (biphephos)-1. Attempted recycling of the catalyst using a thermomorphic multicomponent solvent (TMS) phase-separation procedure proved ineffective because the final product 2 and the Rh-biphephos catalyst were always found in the same polar phase. Auto-oxidation of the linear aldehyde 2 into the fatty 10-cyano-2-methyldecanoic acid (5) proceeds readily upon exposure to air at room temperature, opening a new effective entry toward polyamide-12. Copyright
