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Diphenylphosphinite derivatives of carbohydrates (L-rhamnose, D-mannitol, and cellulose), which have asymmetric centers on the skeletons were synthesized. Asymmetric hydrogenations of prochiral substrates using rhodium catalysts with the prepared chiral phosphinite ligand were carried out to obtain chiral substances in 8–78% optical yield.

A new procedure for reducing a phosphinate (LO) into the corresponding phosphinite (L) includes the following steps: LO → LS → CpNi(I)L → NiL4→ L (Cp = cyclopentadiene); such a scheme is illustrated by the syntheses of 2-phenyl-1,2-oxaphospholane and 2-phenylisophosphindoline 2-oxide.

High optical yields up to ca. 77% were obtained in the hydrogenation of 2-phenyl-1-butene by use of a rhodium catalyst complexed with an insoluble phosphinite derived from 6-O-triphenylmethylcellulose. Recycling of the catalyst was also investigated.

Diethyl phenylphosphonite and ethyl diphenylphosphinite react with 2-benzylideneindan-1,3-dione(1) to give colourless addition compounds (6) and (8) respectively. The reaction of diethyl methyl phosphite and ethyl dimethyl phosphite with (1) leads to the formation of the corresponding phosphonates (9) and (11). Possible reaction mechanisms are considered and the structural assignments are based on chemical and spectroscopic evidence.

o-Azidophenol reacts with methyl diphenylphosphinite to give the amino(oxy)phosphorane, 2-methoxy-2,2-diphenyl-2,3-dihydro-1,3,2-benzoxazaphosph(V)ole (1; 90%), which is also produced (55%) from o-aminophenol, the phosphinite, and N-chlorodi-isopropylamine; o-azidophenyl benzoate reacts with hexa-methylphosphorous triamide to give 2,2-di(dimethylamino)-1,3,2-benzoxazaphosphole (2; 76%) and NN-dimethylbenzamide.

1. o-Diethyl- and o-diphenylphosphinylphenol and o-(2-diethylphosphinylethyl)phenol are prepared by dealkylating the corresponding o-phosphorus-substituted anisoles with hydrobromic acid. 2. o-Diethyl- and o-diphenylphosphinylmethylphenol are prepared by Arbuzov rearrangement of the corresponding salicyl phosphinite esters. 3. o-(2-Diphenylphosphinylethyl)phenol is prepared by cleavage of coumaran with sodium diphenylphosphide followed by oxidation of the resulting phosphinophenol.

The reaction of [ReX(CO)5] (X=Br, H) with the bidentate phosphinite ligand 1,2-bis(diphenylphosphinite)ethane (L–L), synthesized by reaction of PPh2Cl and ethylene glycol in a 2:1 ratio in the presence of NEt3, at room temperature, affords the mononuclear rhenium(I) complexes fac-[ReBr(CO)3(L–L)] (1) and fac-[ReH(CO)3(L–L)] (2). The coordination geometry of the complexes was established by diffraction studies and confirmed by spectroscopic data of both complexes. Compound 1 crystallizes in the P21/c (No. 14) monoclinic space group while the hydride complex does so in P21 (No. 4). The coordination polyhedron around the rhenium atom in both cases is a slightly distorted octahedron with three carbonyl groups in facial positions. The link of the bidentate ligand to the metal atom leads to a seven-membered ReP2O2C2 ring, adopting a conformation better described as a twisted chair.

The rhenium complexes [ReOCl3L2] and [ReCl3L3][L = PPh2OMe, PPh2OEt, PPh2OPri, PPh(OEt)2 or PPh(OPri)2] were prepared by allowing [ReOCl3(AsPh3)2] to react with the appropriate amount of phosphinite or phosphonite. Treatment of [ReCl3L3] with CO and p-MeC6H4NC afforded the mer-trans-[ReCl(CO)3L2] and [ReCl2(p-MeC6H4NC)4L]BPh4 complexes, respectively. Treatment of [ReOCl3L2] with NaBH4 gave [Re2H8L4], but in the presence of phosphinite or phosphonite the trihydrides [ReH3L4] were obtained. Treatment of [ReCl3L3] with NaBH4 gave instead pentahydride complexes [ReH5L3]. All the multihydrides were characterised as ‘classical’ species by variable-temperature NMR spectroscopy (1H and 31P) and T1 measurements. Protonation of [Re2H8L4] and [ReH3L4] with HBF4·Et2O gave the classical hydride cations [Re2H9L4]+ and [ReH4L4]+, respectively, while similar treatment of [ReH5L3] gave a species formulated as containing an η2-H2 ligand, [ReH4(η2-H2)L3]+ on the basis of T1(min) evidence.

A series of new Vaska-type complexes trans -[IrX(CO)L 2 ] (XCl, LP(OEt)Ph 2 ( 1 ), P(OEt) 2 Ph ( 2 ), P(O- o -C 6 H 4 Ph) 3 ( 3 ), P(OPr i ) 3 ( 4 ), P(OBu n ) 3 ( 5 ); XI, LP(OEt)Ph 2 ( 6 ), P(OEt) 2 Ph ( 7 ), P(O- o -C 6 H 4 Ph) 3 ( 8 ), P(OBu n ) 3 ( 9 ) are prepared and characterized. In solution complex 8 undergoes slow cyclometallation to give [IrHI(CO){P(O- o -C 6 H 3 Ph)(O- o -C 6 H 4 Ph) 2 } {P(O- o -C 6 H 4 Ph) 3 }] ( 10 ). The oxidative addition of H 2 to 1–9 occurs stereospecifically with cis addition of H 2 parallel to the XIrCO axis rather than perpendicular to the axis, leading to cis , trans -[IrH 2 X(CO)L 2 ] with a trans disposition of the two L ligands. This direction of H 2 addition is not in agreement with a prior suggestion based on ab initio quantum chemical calculations.

This research was financially supported by Imperial College. The Royal Society (RG140579) and EPSRC (EP/K030760/1) are acknowledged for further funding. J. M. P. thanks the MICINN (Spain, FPI program, EEBB-I-14–08372) for an internship fellowship.

A Rh-cyclodextrin phosphinite catalyst exhibits substrate selectivities in hydroformylation of C8 and C10 olefins due to the inclusion of substrates in the cyclodextrin cavity.

New chiral cationic phosphinite ligands based on ephedrine or valinol skeletons, and corresponding zwitterionic hydridotricarbonylferrate complexes are described. IR data indicate an unusual cis-H–Fe–P arrangement in these complexes, and NMR studies show an unusual variation of 2JPH with temperature and solvent. The possibility that both these rare features are dictated by a stabilizing back folding of the [NMeR2]+ terminus onto the [FeH]− center is discussed.

The ligands (S)- N -(diphenylphosphino)-2-diphenylphosphinoxymethylpyrrolidine, (S)-prolophos, and (S)-1-diphenylphosphinoxy-2- N -diphenylphosphinoaminobutane, (S)-butaphos, have been prepared. The Rh(I) complexes of these phosphines act as efficient homogenous hydrogenation catalysts at ambient temperature and pressure for A -N-acetaminoacrylic acid and itaconic acid.

A new procedure for reducing a phosphinate (LO) into the corresponding phosphinite (L) includes the following steps: LO → LS → CpNi(I)L → NiL4→ L (Cp = cyclopentadiene); such a scheme is illustrated by the syntheses of 2-phenyl-1,2-oxaphospholane and 2-phenylisophosphindoline 2-oxide.

Attempts to distil dialkyl phosphoroisoseleno-cyanatidite (V) caused its rearrangement to dialkyl cyanophosphoroselenoate (VIII), and treatment of (V) with the phosphinite (VI) gives dialkyl phosphorocyanidite (IV); these observations indicate the thermodynamic instability of the intermediate dialkyl phosphoroisocyanidite (III), which has not been identified by physical methods but is supported by the proposed reaction mechanism.

Threophos (IV) ist ein starker dreizahniger Ligand, der aus Threoninmethylesterhydrochlorid (I) hergestellt wird, wie im Formelschema skizziert, und der die symmetrische Hydrovinylierung von z.B. Cyclohexadien ( VI) katalysiert, wenn er im Komplexsystem Ni( COD); /AlEt, C1/( 2R,3R)-Threophos zum Einsatz kommt.

High optical yields up to ca. 77% were obtained in the hydrogenation of 2-phenyl-1-butene by use of a rhodium catalyst complexed with an insoluble phosphinite derived from 6-O-triphenylmethylcellulose. Recycling of the catalyst was also investigated.

Consecutive substitutions of chlorine in dichlorophenylphosphine by lithium cinchoninate and arylcyanocuprates lead stereoselectively to the corresponding R P III esters ; the latter are converted, by methyllithium, into chiral phosphines.

The Cu(I) complex of (1R,3R)-bis(diphenylphosphinoxy)-1,3-diphenylpropane (BDPODP) has been prepared and used for the transfer of the ligand to Rh(I). The Rh(I) complexes of this new phosphinite obtained by this method act as efficient asymmetric homogeneous hydrogenation catalysts for (Z)-α-(acylamino)-cinnamic acids.

We studied the kinetics of the alkaline and neutral aqueous hydrolysis of the ethyl ester of bis(chloromethyl) thiophosphinic acid. Replacement of the P=O group by P=S in ethylbis(chloromethyl)phosphinite increases the rate of the reaction with water and reduces that of the reaction with the OH− ion.

Alkyl diphenylphosphinites react with dialkyl acetylenedicarboxylates in the presence of carbon dioxide to form 1,2-oxaphosphol-3-enes (5) which in the presence of excess phosphinite decompose to give di-ylides (6). The 1,2-oxaphosphol-3-enes (5) from dialkyl phenylphosphonites and trialkyl phosphites react with a further phosphorus component to give the ylides (9) which can readily be converted into dialkyl 1,2,2-tris(alkoxycarbonyl)ethylphosphonates (11). Studies using 13C- and 2H-labelled precursor provide evidence for rearrangement occurring via ketene intermediates.

Diethyl phenylphosphonite and ethyl diphenylphosphinite react with 2-benzylideneindan-1,3-dione(1) to give colourless addition compounds (6) and (8) respectively. The reaction of diethyl methyl phosphite and ethyl dimethyl phosphite with (1) leads to the formation of the corresponding phosphonates (9) and (11). Possible reaction mechanisms are considered and the structural assignments are based on chemical and spectroscopic evidence.

A number of new arenetricarbonylchromium compounds have been synthesized in which the arene ring is substituted with a number of large groups such as t-butyl. Also prepared were the Ph3PCr(CO)2 and (PhO)3PCr(CO)2 analogues of these compounds and of more lightly substituted arenes, and a number of chelate compounds incorporating a short chain attached at C1 of the arene and bonded to chromium by phosphine, phosphite or phosphinite phosphorus atoms. The 13C n.m.r. spectra of these compounds have been recorded, and examined for evidence of stereo-specific influences of phosphorus on the chemical shifts of the arene ring carbons, but no such effects were found. 31P n.m.r. chemical shifts are also reported for these compounds.

o-Azidophenol reacts with methyl diphenylphosphinite to give the amino(oxy)phosphorane, 2-methoxy-2,2-diphenyl-2,3-dihydro-1,3,2-benzoxazaphosph(V)ole (1; 90%), which is also produced (55%) from o-aminophenol, the phosphinite, and N-chlorodi-isopropylamine; o-azidophenyl benzoate reacts with hexa-methylphosphorous triamide to give 2,2-di(dimethylamino)-1,3,2-benzoxazaphosphole (2; 76%) and NN-dimethylbenzamide.

The following phosphinites as derivatives of the unknown diphenylphosphinous acid with phosphorus(III) of the type (C6H5)2POX (X=H, NH4, S(O)R, P(C6H5)2) are normally unstable in the free state. However, they can be stabilized in the protecting coordination sphere of transition metal complexes by building them up by direct or indirect methods. The simple starting molecule is, in principle, diphenylphosphane, (C6H5)2PH, which can be functionalized by oxidation or coordination and subsequent substitution and reduction reactions as it is shown in the following scheme

Dimerisation of 1-methylpyridinium ion by coupling at the 4-position can be brought about by treatment with diphenylphosphinite, diphenylthiophosphinite, and diethyl or diphenyl phosphite anions in a range of solvents. Evidence is presented for the intermediate formation of 1,1′-dimethyl-4,4′-(1H,1′H)-bipyridylidene via addition of the phosphorus nucleophile at the 4-position of the pyridinium ring.

Dimers of 1-aminophosphole oxides react with trichlorosilane–pyridine at the 7-phosphanorbornene moiety to provide the anti-chloro derivative, useful for preparing other compounds. With sodium methoxide, chlorine displacement occurs smoothly to give exclusively the anti-phosphinite. This ester has been treated with benzyl and methyl halides to give tertiary phosphine oxides. The chloro compound reacts with methanol to give the same phosphinite, along with some of the secondary phosphine oxide from cleavage of the methyl group. The secondary phosphine oxide, with anti-oxygen, is the exclusive product of the hydrolysis of the chloride. The complete retention of configuration in these reactions, also observed previously in arylation with phenyl Grignard reagent and in a bromide-exchange reaction, is consistent with a mechanism involving a phosphoranide intermediate whose decay is governed by rules laid down for true trigonal bipyramidal intermediates.

Nucleophilic displacement of esteric alkyl groups in phosphinite esters is enhanced by the presence of transition metal ion species.