A-Hydroxyphosphines

Yamagishi, T., Yokonatsu, T., Suemune, K., and Shibuya, S., Enantioselective synthesis of a-hydroxyphosphinic acid derivatives through hydrophosphi-nylation of aldehydes catalyzed by Al-Li-BINOL complex, Tetrahedron, 52, 11725, 1996. 

Diastereoselective synthesis of p-substituted a-hydroxyphosphinates (252) and (253) by hydroxyphosphinylation of a-silyloxy aldehydes (254) and a-amino aldehydes (255) with ethyl allylphosphinate (256), catalysed with lithium phenoxide, has been reported (Figure 47). ... 

Excellent activities in the coupling of all kinds of aryl chlorides were achieved by use of catalyst 13 containing the bulky bis(adamantyl)( -butyl)phosphane. TONS of 10 to 2 X 10 were recorded even for non-activated aryl chlorides [23]. Quite recently, phosphine oxides according to the equilibrium in eq. (4) were used with Pd2(dba)3 in the Suzuki coupling of aryl chlorides, while a hydroxyphosphine complex/Ni(COD)2 catalyzes the Kumada coupling of the same substrates [26],... 

The polarographic reduction of triphenylphosphine oxide and trioctyl-phosphine oxide at low concentration in nitroethane has been studied. The estimation of phosphate insecticides by polarography has been reported, and the rearrangement of a-hydroxyphosphinates has been followed by conductance. ... 

Phosphinates and phosphonates have been added to the carbonyl groups of the L-oxosugar (12) to give the a-hydroxyphosphinates (13) to (15). The... 

All the substances 104-110 were evaluated as ATCase inhibitors, using E. coli Histidine-tagged C3 ATCase [100]. All inhibition constants ranging from 190 to 3,600 nM were at least ten times higher than the value of 16 nM of the reference molecule PALA. The best inhibition constant was found for the a-hydroxyphosphinic acid 105 = 190 nM). The cyclic azaphosphinanes 106... 

The trimethylsilyl derivative 109 was chosen because its optical purity can be easily increased by recrystallisation until a virtually enantiopure compound is obtained in 56% yield. Some screening showed that polyamines such as PMDETA in combination with. s-BuLi constitute the optimum conditions in order to minimise undesired functionalisation of the methylene group. Under these conditions, 109 was regioselectively lithiated and the carbanion further elaborated by known methods to afford, after a standard desilylation step, a-hydroxyphosphine sulfide 110 (55% yield, 94% ee) and p-hydroxyphosphine sulfide 111 (50% yield over two steps, 96% ee). The method was also adapted to yield diphosphine sulfides 112 (69% yield, 90% ee) and 113 (46% yield, 99% ee). The latter compound is indeed the disulfide of (5, 5)-t-Bu-MiniPHOS. During its synthesis it was observed that no meso compound was formed. 

Trofimov et al. accomplished the addition of bis(phenylethyl)phosphine-oxide and -sulfide to aldehydes and ketones to afford the corresponding a-hydroxyphosphine oxides/sulfides (Scheme 27). ... 

Probably the presence of a second ligating group in the ligand enhances the stability of phosphine oxide-rhodium complexes [177]. Thus, the group of Alper utilized successfully a-hydroxyphosphine oxides, which work, for example, in the reaction of HPPh2 with benzaldehyde (Scheme 2.53) [178], as promoting ligands in the rhodium-catalyzed hydroformylation [179]. 

Scheme 2.53 Preparation of a-hydroxyphosphine oxides (in the paper no information is given as to where the oxygen for the oxidation of the phosphine group comes from).

Sodium iodide acetic acid a-Hydroxyphosphine oxides from 0X0 compds. 

SCHEME 4.131 Microwave-assisted synthesis of a-hydroxyphosphine oxides [226],... 

The electrochemical reduction of mono- and bis(acyl)phosphine oxides was observed to lead to the corresponding radical anions/ In the field of optically active phosphine oxides, the resolution of l-butyl-3-methyl-3-phospholene oxide with TADDOL derivatives was described/ The preparation of the enantiomers of BINAP and its derivatives was summarized in a review/ The deracemization of tert-butyl-phenylphosphine oxide using dibenzoyltartaric acid afforded one enantiomer in a configurationally stable form, in contrast to suggestions in the literature and to general opinion. The enantiomer of the secondary phosphine oxide was utilized in the preparation of a-hydroxyphosphine oxides (Scheme 64). The adducts were obtained in >95% ee and in >95% de. °... 

Diastereoselective reaction of the chiral aldehyde (Fig. 8.3) with diethylphos-phife was mediated by LLB catalytic system (Ln/Li/BINOL) with the diastereoi-somers ratio 75 25, same transformation catalyzed by ALB system gave 80 20 ratio of the diastereoisomers [173]. Synthesized j -amino-a-hydroxyphosphinic acids were considered as key intermediates in the preparation of potential inhibitors of human renin and HIV-protease. 

This reaction was utilized for (5)-ALB catalyzed diastereoselective synthesis /i-amino-a-hydroxyphosphinates by hydrophosphonylation of A,A-dibenzyl-a-ami-noaldehydes with (EtO)EtP(0)H (Scheme 8.76) [192]. 

Yamagishi T, Suemune K, Yokomatsu T, Shibuya S (2002) Asymmetric synthesis of /J-amino-a-hydroxyphosphinic acid derivatives through hydrophosphinylation of a-amino aldehydes. Tetrahedron 58 2577-2583... 

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