Pears that, in asymmetric hydrogenations, Walphos ligands and their biferrocene analogues show drastically various performances. This obtaining becomes much more apparent when, as well as ee values, the absolute configurations of your items are viewed as. This comparison is according to the truth that the sidechain-substituted ferrocene unit of all ligands applied has the R,Sp absolute configuration. For the substrates MAC, MAA, and DMI the item absolute configurations obtained with ligands (R,Sp,Sp)-1 and (R,Sp,Sp)-2 are identical with those obtained with their Walphos analogues (MAC, MAA, S; DMI, R), when those accomplished with ligands (R,Sp,Rp)-1 and (R,Sp,Rp)-2 vary with the substitution pattern in the phosphine substituents. The solution with an S configuration was obtained with (R,Sp,Rp)-1,Table 1. Hydrogenation Benefits Obtained with Walphos Ligands and Their Biferrocene Analoguesaentry 1 2 three four five 6 7 eight 9 10 11 12 13 14 15asubstrate MAC MAC MAA MAA DMI DMI PCA PCA MCA MCA IPCA-D IPCA-D ACA ACA EOP EOPbiferrocene ligand (R,Sp,Sp)-1 (R,Sp,Sp)-2 (R,Sp,Sp)-1 (R,Sp,Sp)-2 (R,Sp,Sp)-1 (R,Sp,Sp)-2 (R,Sp,Sp)-1 (R,Sp,Sp)-2 (R,Sp,Sp)-1 (R,Sp,Sp)-2 (R,Sp,Sp)-1 (R,Sp,Sp)-2 (R,Sp,Sp)-1 (R,Sp,Sp)-2 (R,Sp,Sp)-1 (R,Sp,Sp)-conversn, one hundred 100 one hundred one hundred one hundred one hundred 100 100 one hundred one hundred one hundred 99 100 100 99ee, (confign) 61 (S) 80 (S) 65 (S) 75 (S) 77 (R) 59 (R) 80 (S) 84 (S) 89 (R) 92 (R) 77 (S) 88 (S) 96 (S,S) 98 (S,S) 68 (S) 92 (S)biferrocene ligand (R,Sp,Rp)-1 (R,Sp,Rp)-2 (R,Sp,Rp)-1 (R,Sp,Rp)-2 (R,Sp,Rp)-1 (R,Sp,Rp)-2 (R,Sp,Rp)-1 (R,Sp,Rp)-2 (R,Sp,Rp)-1 (R,Sp,Rp)-2 (R,Sp,Rp)-1 (R,Sp,Rp)-2 (R,Sp,Rp)-1 (R,Sp,Rp)-2 (R,Sp,Rp)-1 (R,Sp,Rp)-conversn, one hundred 100 one hundred one hundred 99 100 100 100 100 one hundred 100 one hundred 100 one hundred 100ee, (confign) 21 (S) 91 (R) 51 (S) 89 (R) 26 (R) 77 (S) 44 (R) 29 (R) 40 (R) 46 (S) 34 (R) 54 (R) 85 (S,S) 80 (S,S) 75 (S) 33 (S)Walphos ligandb SL-W001-1 SL-W002-1 SL-W001-1 SL-W002-1 SL-W001-1 SL-W002-1 SL-W001-1 SL-W002-1 SL-W001-1 SL-W002-1 SL-W001-1 SL-W002-1 SL-W001-1 SL-W002-1 SL-W001-1 SL-W002-conversn, one hundred one hundred 100 100 100 one hundred 100 77 99 100 100 100 100 one hundred 100ee, (confign) 63 (S) 88 (S) 97 (S) 96 (S) 52 (R) 87 (R) 82 (R) 89 (R) 83 (S) 62 (S) 94 (R) 74 (R) 96 (S,S) 85 (R,R) 93 (S) 76 (S)Reaction conditions: for alkenes, 1 mmol of substrate in two.BuyMethyl 6-formylnicotinate five mL of MeOH, reaction time 16 h, 20 , hydrogen pressure MAC, MAA, DMI 1 bar, MCA 20 bar, and PCA, IPCA-D 50 bar, metal precursor [Rh(NBD)2]BF4 (NBD = norbornadiene); for ketones, two.2-Bromo-5-formylbenzoic acid supplier 53 mmol of ACA or 1 mmol of EOP in ten mL of MeOH, reaction time 16 h, 80 , hydrogen pressure 80 bar, additive HCl(aq), metal precursor [RuI2(p-cymene)]2.PMID:22943596 bAbsolute configuration R,Sp.dx.doi.org/10.1021/om401074a | Organometallics 2014, 33, 1945-Organometallics whereas (R,Sp,Rp)-2 resulted in the solution with an R configuration (Table 1, entries 1-6). The hydrogenation of substrates PCA, MCA, and IPCA-D with ligands (R,Sp,Sp)-1 and (R,Sp,Sp)-2, even so, resulted in items that had absolute configurations opposite to those obtained with all the corresponding Walphos ligands SL-W001-1 and SL-W002-1 (Table 1, entries 7-12). The hydrogenation outcomes for ketones ACA and EOP are a lot more constant because, with one particular exception (ACA and ligand SL-W002-1; Table 1, entry 14), the identical product configuration was detected in all circumstances (ACA, S,S; EOP, S). In summary, the original Walphos ligands seem to possess a broader scope of applicability than their biferrocene-based analogues. The replacement of the backbone phenyl ring of Walphos-type ligands.