Bis phosphinic amides

For the first time, an enantioselective cobalt-catalysed hydrovinylation of styrene was achieved with a cobalt-based system bearing a chiral bis(phosphine)amide ligand to produce PhC H(Me)CH=CH2.66... 

Cyclopentadienyl aryl complexes, with niobium, 5, 66 Cyclopentadienyl bis(phosphine)amide zirconium compounds, dicarbonyl complexes, 4, 702. -Cyclopentadienyl-carbanionic complexes, with Zr(IV),... 

Dicarbonyl complexes of mixed cyclopentadienyl bis(phosphine)amide zirconium compounds have also been prepared by ligand-induced disproportionation of (775-C5H5)ZrBH4[N(SiMe2CH2PPr12)2] 47, yielding the bis(tetra-hydroborate) complex (775-C5H5)Zr(BH4)2[N(SiMe2CH2PPr12)2] 48 and the dicarbonyl derivative... 

Also covered by this review are those compounds bearing two or three phosphane units at the same N atom, that is those derived from (H2P)2NH (N-phosphino phosphinous amide in CAS nomenclature) and from (H2P)3N, NJsl-bis(phosphino) phosphinous amide, but not those bearing more than one amino... 

This chapter will also deal with compounds containing two or three phosphinous amide units, which, for simpUcity, will be named here as bis(amino-phosphanes) or tris(aminophosphanes) but not with phosphinous amides containing other additional organophosphorus functionaUties as, for instance, the so-called aminophosphine phosphinites (AMMP), which have been the subject of increasing attention in the Uterature dealing with catalytic asymmetric transformations and have been treated in other reviews [2,3]. 

M,JV-Bis(phosphino) phosphinous amides N(PR2)3, commonly called triphos-phinoamines, are still virtually unknown, with the exceptional reported existence of N(Pp2)3 and N[P(CH3)2]3 [15,19,20]. The usual synthetic approaches to N(PPh2)3 give instead the isomeric Ph2P-P(Ph2)=N-PPh2 [25]. 

Occasionally, attempts at introducing a new PR2 group on the nitrogen atom of an NH phosphinous amide, with the aim of preparing Ar,AT-bis(phosphino) phosphinous amides, result in the generation of monophosphazenes derived from diphosphanes, as seen in the preparation of 20 which occurs by P-P bond formation [74] (Scheme 20). The authors of this work claimed that the electron-... 

Tetrasubstituted phosphinous amides of the type R2NPPh2 have been successfully arylated at phosphorus by the action of bromobenzene, in a process catalyzed by NiBr2, to give the aminophosphonium bromides [R2NPPh3] Br [109]. Other representative members of this class form phosphane-borane complexes [62], are aminated at phosphorus by chloramine to yield bis(amino)phos-phonium salts [110] and have been claimed to be protonated at phosphorus by ethereal tetrafluoroboric acid, as determined by NMR analysis [111]. 

Following the general trend of this account, monodentate phosphinous amide ligands and bidentate AT-phosphino phosphinous amides or bis(amino-phosphanes) are included in the following discussion, but not other bidentate ligands bearing additional, different phosphorus functionalities, as for instance phosphinous amide-phosphane bidentate ligands. 

Phosphinous amides, based on proline and tetrahydroisoquinoline carboxylic acid, bearing a second donor center (50, Ar=Ph R =H, CH3,Tr, Ph R =H, CH3,Tr, Ph and 51, R =H,Tr R =H,Tr) (Scheme 40) have been developed for use in allylic alkylation and amination of substituted propenyl acetates, yielding the corresponding products in 87-98% (5-94% ee) and 29-97% (14-93% ee) respectively [55, 167]. With bidentate ligands of type 38 where R=(S)-PhMeCH, and with the bis(aminophosphanes) 52 (R=Ph) similar allylic alkylations have been also tested [168,169]. 

In recent years, the catalytic asymmetric hydrogenation of a-acylamino acrylic or cinnamic acid derivatives has been widely investigated as a method for preparing chiral a-amino acids, and considerable efforts have been devoted for developing new chiral ligands and complexes to this end. In this context, simple chiral phosphinous amides as well as chiral bis(aminophosphanes) have found notorious applications as ligands in Rh(I) complexes, which have been used in the asymmetric hydrogenation of a-acylamino acrylic acid derivatives (Scheme 43). 

Trimethylsilylimino) (trimethylsilyl) [tris(dimethylamino)phosphoranylidene] methyl phosphine (64), produced by the reaction of [(dichlorophosphanyl)methyl]tris (dimethylamino)phosphonium tetraphenylborate with sodium bis(trimethylsilyl)amide,... 

In contrast to phosphonic acids, H-phosphinic acids can be coupled with alcohols using carbodiimides to give H-phosphinates 83 (Scheme 31, Table 12).[63-1231 These H-phosphinates 83 afford the corresponding phosphonic acids 84 directly by oxidation with NaI04[123l or by treatment with bis(trimethylsilyl)amide followed by carbon tetrachloride, triethylamine, and waterJ63 Alternatively, as described above (Section 10.10.2.1.3), H-phosphinates may also be converted into the phosphonochloridates by oxidation with carbon tetrachloride and then coupled to nucleophiles other than water, f63-75-76 ... 

Base-Catalyzed Reactions of Phosphonomethyl-phosphinates, Bis(phosphonomethyl)phosphinates, and Bis(phosphonomethyl)phosphinic Amides with Aldehydes... 

Chemical Name Phosphinic amide, P,P-bis(l-aziridinyl)-N-ethyl-N-l,3,4-thiadiazol-2-yl-... 

Enyne CM of either terminal or internal alkynes is possible if the ethylene is employed as the CM partner. Initial attempts using bis-phosphine catalyst 2 (3-10%) were only successful if the substrate contained heteroatomic ester or amide functionality at the propargylic position [108]. Later endeavours from... 

C,H24NPSi2, Phosphinous amide, P,P-didi-methyl-Af,lV-bis(trimethylsilyI)-, 25 69 CJH24N9P3, l,3,5,2 ,4X ,6X -Ttiazattiphos-phorine... 

C 3H27NPSi, Phosphinous amide P-methyl-P-phenyl-N,N-bis(trimethyl-sUyl)-, 25 72... 

NPSi2CgH24, Phosphinous amide, P,P-di-methyI-N, N-bis( trime thyIsilyl)-, 25 69 NP2C36H30, Phosphorus(l+), (x-nitrido-bis(triphenyl-... 

PNSiC,3H27, Phosphinous amide, P-methyl-P-phenyl-N, iV-bis(trimethylsilyl)-,... 

Si2NPCgH24, Phosphinous amide, P,P-di-methyl-A, A -bis(trimethylsilyl)-, 25 69 Si2N20QH24, Urea, N,N -dimethy -N,N -bis(trimethylsilyl)-, 24 120 Si2N2SQH,9, Sulfur diimide, bis(trimethyl-silyl)-, 25 44... 

Phosphine Chalcogenides as Ligands. - The complexation of lanthanide and actinide ions by phosphine oxide ligands remains an active area, and a theoretical assessment of the coordination of phosphine oxides (and phosphate esters) by trivalent lanthanide ions has appeared." Trivalent lanthanide complexes of the functionalised enol phosphine oxide (265), (and a related phosphonate), have been describedComplexes of thorium(iv) with bis(di-phenylphosphino) ethane dioxide and bis(diphenylphosphinoyl)amide have also been characterised." Calixarene systems which bear phosphine oxide... 

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