The Pd-catalyzed direct alkylation of H-phosphinic acids and hypophosphorous acid with allylic/benzylic alcohols has been described previously. Here, the extension of this methodology to H-phosphinate esters is presented. The new reaction appears general, although its scope is narrower than with the acids, and its mechanism is likely different. Various alcohols are examined in their reaction with phosphinylidene
Shown is the preparation and subsequent elaboration of P-chiral compounds that can be used as a building block for many P-chiral ligands used, for example, in asymmetric catalytic reactions. Specifically, a synthesis is shown for RP(O)(OR*)CH
2
OH, with R=H, Ph, aryl, alkyl, and R*=menthol (and other chiral alcohol-derived moieties), especially HP(O)(OMen)CH
2
OH (Men=L-menthol). This versatile building block is easily synthesized via reaction of inexpensive starting materials, H
3
PO
2
, menthol as the chiral auxiliary, and paraformaldehyde.
A General Strategy for the Synthesis of P-Stereogenic Compounds
作者:Olivier Berger、Jean-Luc Montchamp
DOI:10.1002/anie.201306628
日期:2013.10.18
A great leap forward toward the general synthesis of P‐stereogenic compounds: Heating H3PO2 with (−)‐menthol and paraformaldehyde gives easily crystallized menthyl hydroxymethyl‐H‐phosphinate (1). From this product, virtually any P‐stereogenic compound can be synthesized (see picture).
向P-立体异构化合物的一般合成方面迈出了一大步:将H 3 PO 2与(-)-薄荷醇和多聚甲醛加热可轻松结晶出羟甲基H-次膦酸薄荷基酯(1)。从该产品,几乎可以合成任何P立体异构化合物(参见图片)。