tertiary phosphines bearing an o-bromo (or iodo)aryl substituent is described. The key step of this synthesis is based on the reaction of a secondary phosphineborane with the 1,2-dibromo (or diiodo)arene, owing to the formation in situ of an aryne species in the presence of n-butyllithium. When P-chirogenic secondary phosphineboranes were used, the corresponding o-halogeno-arylphosphine boranes were
申请人:CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (CNRS)
公开号:US20140142325A1
公开(公告)日:2014-05-22
Novel P-chirogenic organophosphorus compounds of general formula (I), a process for the synthesis of the compounds of formula (I), and intermediate products of general formulae (II), (III) and (IV), as shown below, are involved in the synthesis of compounds (I).
Metal complexes including compounds (I) as ligands are also described. The novel compounds and complexes are useful in asymmetric catalysis by transition metal complexes or organocatalysis, especially for asymmetric hydrogenation or allylation. Compounds of general formula (I) may be useful as agrochemical and therapeutic substances, or as reagents or intermediates for fine chemistry.
Efficient Stereoselective Synthesis of <i>o</i>-Functionalized P-Chirogenic Phosphines Applied to Asymmetric Catalysis
作者:Jérôme Bayardon、Sylvain Jugé
DOI:10.1080/10426507.2014.993760
日期:2015.6.3
The stereoselective synthesis of P-chirogenic o-halogenophenylphosphines and their use for the preparation of o-functionalized derivatives are reported. The key step of this synthesis is based on the reaction of a P-chirogenic secondary phosphine borane, previously prepared using ephedrine methodology, with n-butyllithium (1.2 equiv.) and 1,2-dihalogenobenzene. The reaction proceeds by addition of the phosphide borane to the benzyne generated in situ from 1,2-dihalogenobenzene by metal-halide exchange with the intermediate carbanion. The o-halogenophenylphosphine boranes were obtained with retention of configuration at the P-center and with enantioselectivities up to 99% ee. The free o-halogenophenylphosphines were applied for the preparation of various kinds of o-functionalized P-chirogenic phosphines useful in asymmetric catalyzed reactions.