Allyl functionalized phosphinite and phosphonite ligands: Synthesis, transition metal chemistry and orthopalladation reactions

Abstract

Allyl functionalized phosphinite PPh2(OAr) [Ar=C 6H4(o-C3H5)] (1) and phosphonite PPh(OAr)2 (2) ligands were prepared by the reactions of 2-allylphenol with PPh2Cl and PPhCl2, respectively. The ruthenium(II) complexes, [Ru(η6-p-cymene)(PPh2(OAr))Cl2] (3) and [Ru(η6-p-cymene)(PPh(OAr)2Cl2)] (4) were obtained by reacting 1 or 2 with [Ru(η6-p-cymene)Cl 2]2 in 2:1 molar ratios, respectively. Reactions of 1 or 2 with AuCl(SMe2) gave [Au{PPh2(OAr)}Cl] (5) or [Au{PPh(OAr)2}Cl] (6) in good yield. The palladium complex, [Pd{PPh(OAr)2}2Cl2] (7) was prepared by reacting Pd(COD)Cl2 with 2 in 1:2 molar ratio. The reaction between Pd(COD)Cl2 and 1 yielded a mixture of orthopalladated cis- and trans-[Pd(Ph2P(OAr))Cl]2 (8a and 8b). The treatment of 8 with PPh3 and Ph2PCH2PPh2 resulted in the cleavage of chloro bridge to give respectively, [Ph2(OAr) PPd(PPh3)Cl] (9) and [Ph2(ArO)PPd(η2-dppm)] OTf (10). Single crystal X-ray structure of the ruthenium complex 3 is described. © Indian Academy of Sciences.