Highly Selective Catalyst Systems for the Hydroformylation of Internal Olefins to Linear Aldehydes

Rhodium-Biphephos-Catalyzed Tandem Isomerization–Hydroformylation of Oleonitrile

“…Oleonitrile (1) Hydroformylation products (2) and (3) derived from Oleonitrile: Typical signals for these aldehydes were observed in 1 H NMR (CDCl 3 , 400 MHz, 298 K) at δ = 9.71 (t, J = 2 Hz, 1H) ppm for linear aldehyde (2) and at δ = 9.62-9.50 (d, J = 2 Hz, 1H) ppm for the branched aldehydes (3). The aldehyde signals were also evidenced in 13 C{ 1 H} NMR (CDCl 3 , 100 MHz, 298 K): the linear aldehyde appeared at δ = 202.7 ppm; all branched aldehydes were found in the range δ = 200.14-205.46 ppm.…”

“…The synthesis of linear aldehydes is of high interest for industrial purposes, and very high regioselectivities (l/b > 99:1) have been achieved from terminal alkenes with rhodium catalysts using bulky bisphosphine (e.g., Bisbi [2] and Naphos [3]) and bisphosphite (e.g., Biphephos [4]) ligands. However, the selective formation of linear aldehydes is much more challenging when starting from internal alkene as, in this case, preliminary isomerization of the C=C bond is necessary to bring it to the terminal position before performing the hydroformylation process itself.…”

Highly Regioselective and Active Rhodium/Bisphosphite Catalytic System for Isomerization–Hydroformylation of 2-Butene

“…The catalyst must perform higher isomerization rate of internal olefin to terminal olefin (Scheme 2, B) than direct hydroformylation rate of internal olefin (Scheme 2, A), so that the system can maintain a small amount of terminal olefin in the olefin mixture under the thermodynamic equilibrium, as a result of which, once terminal olefin was formed, it would be immediately transformed to aldehyde in the presence of syngas due to the more quick hydroformylation rate of terminal olefin. Meanwhile, if only the activity and regioselectivity for the hydroformylation of the terminal olefin are high enough, the linear aldehyde would be the main product [1, 16,18]. The isomerization-hydroformylation of 2-butene was first investigated using Rh(acac)(CO) 2 /1 as catalyst, and the effects of temperature and molar ratio of ligand to rhodium were summarized in Table 1.…”

“…Likewise, Leeuwen and Zhang have proved the above conclusions [14][15][16][17]. Since 2-PH (2-propylheptanol), the product of condensation and hydrogenation of aldehyde that was obtained by hydroformylation of 2-butene, is superior to the standard 2-EH (2-ethylhexanol) on physical aspects due to environmental consideration and its potential value with the attractive advantage of competition [18], therefore we focused on the isomerization-hydroformylation of 2-butene to n-pentanal. In this study, we screened 2,2 0 -bis(dipyrrolylphosphinooxy)-1,1 0 -(±)-binaphthyl (1) [19,20], 2,2 0 -bis(dipyrrolylphosphinooxy)-1,1 0 -(±)-biphenyl (2) [15], and 2,2 0 -bis(diphenylphosphino)methyl)-1,1 0 -biphenyl (BISBI 3) [21] (Fig.…”

Carbon Monoxide as a Chemical Feedstock: Carbonylation Catalysis

“…Beller and coworkers used NAPHOS, a BISBI analog backbone, substituted with 3,5-bistrifluoromethylphenyl groups as the ligand in rhodium-catalyzed hydroformylation of internal alkenes and obtained high selectivities to the linear product [63].…”