Cinnamoyl amide type chiral P,olefin ligands for Pd-catalyzed reactions

Abstract

We have synthesized cinnamoyl amide type chiral P,olefin ligand and obtained separable diastereomers of 4d and demonstrated Pd-catalyzed asymmetric allylic substitution reactions of indoles using this chiral ligand with high enantioselectivities (up to 98% ee).

Axially chiral N-alkyl-N-cinnamoyl amide type P,olefin ligands for Pd-catalyzed reactions

“…According to the observed stereochemical outcome and our previous reports, 4,5 we propose a possible stereochemical pathway for the formation of ( S )- 4 as a product. As shown in Scheme 3, Pd II complexes such as W-type A and M-type B intermediates were formed from ligand (a R )-(–)- 1c .…”

“…The reaction with 2-, 4-, or 5-substituted indoles also gave the corresponding products (S)-4i-m with high enantioselectivities (entries 10-13). According to the observed stereochemical outcome and our previous reports, 4,5 we propose a possible stereochemical pathway for the formation of (S)-4 as a product. As shown in Scheme 3, Pd II complexes such as W-type A and M-type B intermediates were formed from ligand (aR)-(-)-1c.…”

“…1). We also recently reported N -alkyl- N -cinnamyl type chiral ligands L2 3 and L3 4 with C(aryl)–N(amine) bond axial chirality and an N -cinnamoyl amide type chiral ligand L4 5 with central chirality and C(aryl)–N(amide) bond axial chirality.…”

Palladium‐Catalyzed Enantioselective Indole Allylic Alkylation with Chiral Phosphoramidite‐Selenide‐Based Ligands

“…[7] Besides, the P-Olefin hybrid ligands with axial chirality reported by the Du group [8] and the Zhou group [9] were also proved to be good choice. Recently, the Mino group [10] reported several examples of cinnamoyl amide type and Ntrans-cinnamylaniline type P-Olefin ligands with axial chirality and their applications in asymmetric catalysis, which could furnish the desired product in up to 91 % yield and 98 % ee. An elegant spiro indane-based SMI-PHOX ligands have been developed by Teng and coworkers, which exhibited good catalytic effects to afford the corresponding products with 85-98 % yields and 83-97 % enantioselectivities.…”