Diaminophosphine

The first catalytic dihydroamination of a phosphaalkyne was confirmed when the product diaminophosphine was formed, the complex /ra ,y-[PdCl2 PfPr NII C fBu ) ].255... 

A number of P-chirogenic diaminophosphine oxides (DIAPHOXs) 275 derived from aspartic acid were prepared via hydrolysis of triaminophosphine intermediate 274, generated in a fully diastereoselective reaction of triamines 273 with phosphorus trichloride (Scheme 65) [102, 103],... 

The phosphoramidite ligands that are the focus of the remainder of this chapter have prompted the investigation of ligands containing related structures. Iridium complexes of aspartic acid-derived P-chirogenic diaminophosphine oxides (DlAPHOXs) catalyze the amination [62] and alkylation [63] of aUyhc carbonates (Scheme 6). With BSA as base and catalytic amounts of NaPFs as additive, branched amination and alkylation products were obtained from cinnamyl carbonates in excellent yields and enantioselectivities. However, the yields and enantios-electivities were lower for the reactions of alkyl-substituted aUyhc carbonates. Added LiOAc increased the enantioselectivities of aUyhc alkylation products. 

One of the most powerful strategies for asymmetric ring construction is to desymmelrize a preformed ring. Yasamusa Hamada of Chiba University in Japan has reported (J. Am. Chem. Soc. 2004, /26, 3690) that the inexpensive diaminophosphine oxide 2 nicely catalyzes the asymmetric alkylation of the cyclohexanone carboxylate 1 to give 3. Although no examples were given, this asymmetric alkylation would probably work as well with heterocyclic P-ketoesters. 

A ruthenium catalyst derived from a secondary diaminophosphine oxide has been used successfully in the arylation of C-H bonds by aryl tosylates.41... 

Complex compounds obtained on the basis of phosphoranimine 409 [712a] and diaminophosphine 410 [520] ligands are of considerable interest. Complex compounds of the types 408 and 410 are represented in general by chelates, and 409 by cluster structures. N,P-Bidentate ligands and their rhodium and palladium complexes are described in a recent review [712b],... 

Thio analogs of these compounds, for example, PhP(S)(NHR)2 can also be prepared similarly, from the corresponding thiophosphonic halides and amines or by oxidative addition of sulfur to diaminophosphines, RP(NR92 Phenylphosphonic acid diamides, PhP(Q)(NHBu )2 (Q = S, Se) were prepared from PhP(NHBfr)2 by oxidative addition of sulfur or selenium and the 0x0 derivative PhP(0)(NHBu )2 by oxidation with tert-butyl peroxide. Their lithiation produces unusual cyclic or polycyclic dUithium salts of the phosphonate dianions [PhP(Q)(NBfr)2] (Q = O, S, Se). The dimethylaluminum derivatives PhP(Q)(NBu )2AlMe2 (Q = S, Se) obtained from PhP(Q)(NHBu )2 with AlMes are fom-membered chelate rings. ... 

Chiral bidentate ligands such as diphosphinites, diaminophosphines and aminophos-phine-phosphinites, 2 2 have also been used. Although much information has been accumulated the choice of chiral catalysts and reaction conditions still remains empirical, and one must make an effort to find the most suitable catalytic system and reaction conditions for every new substrate. 

Miscellaneous. - Several new optically active tervalent phosphorus acid derivatives have been prepared for use as ligands in asymmetric metal catalysed reactions. These include the cyclic diaminophosphines 57, the cyclic bisamino-phosphine 58, and the compounds 59, 60, 61, and 62 containing a 1,1 -binaphthalene group as the chiral inducer. A new diphosphoramidite (63) has been used for improved regioselectivity of rhodium-catalysed hydroformylations of alkenes. A new sterically hindered chiral phosphite (64) derived from glucose and a Cu(I) complex of 64 have been prepared. ... 

The problem of achieving selective monoarylations of 2-arylpyridines was solved by applying a sterically hindered diaminophosphine oxide (72) as preligand [60]. This air-stable preligand allowed the use of tosylates as electrophiles, which are easily... 

Cyclic diaminophosphine oxide 35 ligating to Pd is useful for substitution of allylic carbonates. To access diamines from 2-vinylaziridines the catalyst system constituting 29 meets established standards/ ... 

Aminohalophosphines can be prepared from dihalophosphines and 2 mol of an amine (equation 36) or simply by mixing a diaminophosphine with a dihalophosphine. The latter method gives a pure product in high yield, e.g. equations 53 and 54 ". ... 

Nemoto and Hamada [50] has described the development of a new class of chiral phosphorus ligand - aspartic acid-derived P-chirogenic diaminophosphine oxides, DIAPHOXs - and their application to several Pd-catalyzed asymmetric allylic substitution reactions. Pd-catalyzed asymmetric allylic alkylation was initially examined in detail using diaminophosphine oxides 77, resulting in the highly enantioselective construction of quaternary stereocenters. With the use of the Pd-DIAPHOX catalyst system, asymmetric allylic alkylation, asymmetric allylic amination, and enantioselective construction of quaternary carbons were achieved with high ee (up to 97-99% in many cases) (Scheme 24). 

Kaboudin and Yokomatsu reported the diastereoselective addition of a-substituted a-amino-//-phosphinates 304 to imines catalyzed by Lewis acids. Among Lewis acids, Yb(OTf)3 was found to be the best catalyst. With this catalyst the a,a -diaminophosphinic derivatives 305 were obtained with des ranging from 10% to 95%. The structure of product 305 was determined by X-ray analysis as shown in Scheme 102. The reaction proceeded with retention of configuration at the phosphorus atom [200, 201]. 

Nemoto T (2008) Transition metal-catalyzed asymmetric reactions using P-chirogenic diaminophosphine oxides DIAPHOXs. Chem Pharm Bull 56 1213-1228... 

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