MOP‐Type Binaphthyl Phosphite and Diamidophosphite Ligands and Their Application in Catalytic Asymmetric Transformations

Abstract

Monodentate phosphite and diamidophosphite ligands have been developed based on Omethyl-BINOL. These chiral ligands are easy to prepare from readily accessible phosphorylating re-The new ligands have demonstrated excellent enantioselectivity in the palladium-catalysed allylic substitution reactions of (E)-1,3-diphenylallyl acetate with sodium p-toluenesulfinate (up to 99 % ee), pyrrolidine (up to 97 % ee), dipropylamine (up to 95 % ee) and dimethyl malonate (up to 99 % ee). In the palladium-catalysed deracemization of ethyl (E)-1,3-diphenylallyl carbonate, up to 96 % enantioselectivity has been achieved. The diamidophosphite ligands have exhibited very good enantioselectivity in the Rh-catalysed asymmetric hydrogenation of dimethyl itaconate (up to 90 % ee).

Asymmetric Catalytic Reactions Using P*‐Mono‐, P*,N‐ and P*,P*‐Bidentate Diamidophosphites with BINOL Backbones and 1,3,2‐Diazaphospholidine Moieties: Differences in the Enantioselectivity

“…[11] Rh-catalyzed hydrogenation of a-dehydrocarboxylic acid esters 14a, b was performed as published. …”

“…[23] However, we used a unique procedure carried out in anhydrous CH 2 Cl 2 with the formation of (Bu) 4 NHCO 3 salt directly (in situ) in organic media. [11] Under these conditions and at the molar ratio L/Pd = 1, both ligands (S a )-7 and (R a )-7 provided moderate conversion of 10, and essentially equally good levels of asymmetric induction (90% and 87% ee) with (S) and (R) configuration of 11, respectively (Table 6, entries 1 and 3). It is interesting, that the increase of the L/Pd molar ratio gave rise to product 11 having opposite absolute configuration (Table 6, entries 1,2 and 3,4).…”

“…[9] NOBIN-based P,N-bidentate phosphites L G,H are highly efficient in the Cu-catalyzed enantioselective conjugate additions, and P-monodentate MOP-type compounds L I,J were shown to have good to excellent enantioselectivity in the Pd-catalyzed allylation and in the Rh-catalyzed hydrogenation. [10,11] In the last few years, we have developed a new class of highly modular diamidophosphite ligands with 1,3,2-diazaphospholidine rings that promote a wide range of catalytic asymmetric reactions. [12] It should be noted that these P*-chiral 1,3,2-diazaphos- Figure 1.…”

Palladium-Catalyzed Enantioselective Allylic Substitution

“…32). Gavrilov developed ligands L93-L95 [126,128,129], while Lyubimov worked on L96 [130]. When the oxygen side chain was not chiral, formation of the S product was favored in AAA.…”

“…These phosphorus chlorides were then reacted with alcohols or amines, chiral or not, to give phosphites and phosphoramidites, respectively. Standard AAA results were only recorded for L90 in the past few years, with an ee of 72% [126]. L91 was used in asymmetric allylation with an allylic alcohol [127].…”