Chiral 4-(Diphenylphosphanyl)-1-(dialkylamino)butane Ligands – Synthesis, Applications in Asymmetric Alkylation and Theoretical Study

✍ Scribed by Fabien Robert; Françoise Delbecq; Christelle Nguefack; Denis Sinou

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 347 KB
• Volume: 2000
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/(sici)1099-0682(200002)2000:2<351::aid-ejic351>3.0.co;2-q

✦ Synopsis

Various

4-(diphenylphosphanyl)-1-(dialkylamino)butane important role played by two factors in the alkylation reaction: steric control, leading to the formation of a unique ligands were prepared from commercial (2S,3S)-2,3-Oisopropylidene-d-threitol. These ligands, associated with diastereoisomer of the π-allylpalladium complex, and orbital control, which orients the attack of the nucleophile trans to Pd 2 (dba) 3 , gave enantioselectivities of up to 75% in the alkylation of racemic 1,3-diphenylprop-2-enyl acetate with the phosphorus atom. dimethyl malonate anion. A theoretical study shows the gave the azido alcohol 5 in 95% yield (Scheme 2). Reduction CPE Lyon, Universite ´Claude Bernard Lyon 1, of compound 5 with molecular hydrogen in the presence of 43, bd du 11 novembre 1918, F-69622 Villeurbanne Cedex, France 20% Pd/C led quantitatively to the amino alcohol 6. Con-