Polymer-supported phosphoramidites: highly efficient and recyclable catalysts for asymmetric hydrogenation of dimethylitaconate and dehydroamino acids and esters

✍ Scribed by Simon Doherty; Edward G. Robins; Ibolya Pál; Colin R. Newman; Christopher Hardacre; David Rooney; Damian A. Mooney

• Book ID: 104359813
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 670 KB
• Volume: 14
• Category: Article
• ISSN: 0957-4166
• DOI: 10.1016/s0957-4166(03)00253-2

✦ Synopsis

Several novel phosphoramidites have been prepared by reaction of the primary amines para-vinylaniline, ortho-anisidine, 2-methoxyphenyl(4-vinylbenzyl)amine, 8-aminoquinoline and 3-vinyl-8-aminoquinoline with (S)-1,1%-bi-2-naphthylchlorophosphite, in the presence of base. Rhodium(I) complexes of these phosphoramidites catalyse the asymmetric hydrogenation of dimethylitaconate and dehydroamino acids and esters giving ee values up to 95%. Soluble non-cross linked polymers of the para-vinylaniline and 3-vinyl-8-aminoquinoline-based phosphoramidites have been prepared by free radical co-polymerisation with styrene in the presence of AIBN as initiator. The corresponding [Rh(COD)] + complexes serve as recyclable catalysts for the asymmetric hydrogenation dimethylitaconate and dehydroamino acids and esters to give ee values up to 80%.