Synthesis of Phosphaguanidines by Hydrophosphination of Carbodiimides with Phosphine Boranes
摘要:
The direct addition of anionic secondary phosphine boranes to carbodiimides yields both chiral and achiral phosphaguanidine boranes, under ambient temperature conditions. An analogous preparation of menthol-derived phosphinite boranes is also described. These products can be deborinated to give the corresponding phosphines, and subsequently oxidized to give phosphine oxides. The robustness of this method was further demonstrated in the synthesis of structurally novel cyclic phosphaguanidines.
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
Novel Synthesis of P-Chiral Hydroxymethylphosphine–Boranes through Lipase-Catalyzed Optical Resolution
作者:Kosei Shioji、Yoshimitsu Kurauchi、Kentaro Okuma
DOI:10.1246/bcsj.76.833
日期:2003.4
A novel approach toward the lipase-catalyzed acylation of alkyl(1-hydroxymethyl)phosphine–boranes was achieved. Up to 99% of enantiomerically enriched phosphine–boranes was obtained by using lipase AK and CAL.
实现了脂肪酶催化烷基(1-羟甲基)膦硼烷酰化的新方法。通过使用脂肪酶 AK 和 CAL,获得了高达 99% 对映体富集的膦硼烷。
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.