Two new syntheses of the “phospha-wittig” reagents

✍ Scribed by Siegfried Bauer; Angela Marinetti; François Mathey

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 406 KB
• Volume: 2
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/hc.520020209

✦ Synopsis

Abstract

The secondary phosphorylphosphane complexes used in the synthesis of phosphaalkene complexes from carbonyl compounds by the so‐called „phospha‐Wittig”︁ reaction can be obtained by two routes. In the first one, a primary lithiophosphine complex is condensed with a chlorophosphite. The resulting PP compound is oxidized at the free phosphorus by 3‐chloroperbenzoic acid. In the second one, bis(phosphoryl)phosphane complexes are allowed to react with sodium methylate in methanol or with water. One of the two PP bonds of the starting produt is thus cleaved to give the „phospha‐Wittig”︁ reagent. Both routes give better yields and are less sensitive to steric hindrance than the previously described method.