Search

The reactivity of O-peracetylated and O-perbenzoylated 1-COOMe, 1-CONH

Sixteen cobalt(III) complexes incorporating one of the investigated 4N donor tripodal amines in the presence or absence of differently substituted hydroxamates have been synthesized and the effect of the nature of the N-donor, size of the chelates formed and the effect of the type of the substituent(s) at the hydroxamate moiety on the redox properties of the complexes have been studied. The crystal and molecular structures of the new complexes, [Co(uns-penp)(H 2 O)Cl]Cl 2 ·H 2 O ( 4 ), [Co(tren)(phebha)](ClO 4 ) 2 ( 11 ), [Co(tpa)(bha)](ClO 4 ) 2 ·C 2 H 5 OH·H 2 O ( 15 ) and [Co(tpa)(phebha)](ClO 4 ) 2 ( 16 ) have also been determined by single crystal X-ray diffraction method. Cyclic voltammetric (CV) results indicated the irreversible reduction of Co(III) in all the investigated complexes. Out of the four studied tripodal amines, abap was found to decrease the Co(III/II) reduction potential far below the region of bioreductants. Decreasing of two of the chains by one CH 2 in tren compared to abap resulted in less negative reduction potential of the corresponding complex. Further positive shift was observed by introducing two (uns-penp), and especially three (tpa) π-back-bonding pyridyl rings into the chains of tetramines. In agreement with literature results, the 3+ oxidation state of the central cobalt ion was found to be extremely stabilized in the ternary complexes containing the doubly deprotonated benzohydroximate, but the metal ion is significantly more reducible in the ternary complexes with mono-deprotonated benzohydroxamate/derivative ligands. Measurable effect was not found on the redox potential via introduction of chloro or nitro substituents in para position into the phenyl moiety of bha − (Cl-bha − and NO 2 -bha − ). Significant positive shift (ca. 200 mV) was obtained, however, when R N = H was replaced by a phenyl ring in phebha − therefore complexes with this latter ligand can be likely candidates for the in vitro releasing of hydroxamates with proven biological activity.

The configuration of the ligand's N-substituent was found to determine the stoichiometry and strict stereoselectivity of N-coordination in twelve-membered palladium dimers 2a-b. The novel palladium(II)-complexes 2a-b have been synthesized in the reaction of [Pd(COD)Cl2] and optically pure (S,S)-pentane-2,4-diyl based aminoalkyl-phosphine ligands Ph2PCH(CH3)CH2CH(CH3)NHR 1a-b (R = (R)-α-phenylethyl 1a, R = (R)-α-(1-naphthyl)ethyl 1b) with stereogenic nitrogen atom, and studied by various 1D and 2D NMR techniques in solution and in the case of 2a by single-crystal X-ray diffraction. As an unprecedented case, ligands 1a-b were found to yield exclusively 12-membered cyclic dinuclear Pd(II)-complexes with stereospecific coordination of both of the donor nitrogen atoms. Formation of the 12-membered ring is shown to reduce the steric hindrance of the bulky substituents with respect to the six-membered ring.

Six novel thioether-aminophosphine type ligands with a general formula (Ar1)2PN(R1)CHR2(CH2)nCH(R3)SAr2 has been synthesized. The modular structure of the ligands and the new methodologies developed for their preparation enabled the systematic variation of their bridge length (n = 0 or 1), the substitution pattern of the backbone (R2, R3 = H or Me) as well as the P-, N- and S-substituents (Ar1 = Ph or 3,5-Me2C6H3, R1 = Et or iPr and Ar2 = Ph, 4-MeC6H4, or 4-MeOC6H4, respectively). The ligands proved to be effective in Pd-catalyzed asymmetric allylic etherification reactions providing the products in high yields (up to 95%) and with good enantioselectivities (up to 86%) using unprecedentedly low (0.2 mol%) loadings of the chiral Pd-catalyst. Based on these findings, a new scalable protocol has been developed for the preparation of chiral allylic ethers. Furthermore, the Pd(II) coordination chemistry of the ligands was thoroughly investigated by 1D and 2D NMR methods as well as by X-ray crystallography with special attention to the conformation of the chelate ring and the stereoselectivity of the sulfur coordination. Based on these studies, the main factors determining activity and selectivity of the catalytic system have been identified.

Six-membered chelate complexes of type [Pd(1a-e)Cl2] (2a-e) and [Pd(1a-e)(η3-PhCHCHCHPh)]BF4 (3a-e) of a series of systematically varied chiral phosphine-amine ligands (S,S)-Ph2PCH(CH3)CH2CH(CH3)NHR 1a-e (R = benzyl 1a, R = ethyl 1b, R = (S)-α-phenylethyl 1c, R = isopropyl 1d, R = methyl 1e) have been studied. The complexes 2a-e were characterized by X-ray crystallography, DFT analysis and in solution by 1D and 2D NMR spectroscopy. A very good correlation has been observed between the steric demand of the N-substituent and the distortion of the chelate. Furthermore, it has been proved that sterically more demanding N-substituents are capable of distorting the chelate to a larger extent along one single, well defined conformational pathway. The careful variation of the N-substituent thus allows a precise stereochemical fine tuning of the metal's coordination sphere. As a substantiation of this concept, the investigation of complexes 3a-e revealed that the exo/endo ratio as well as the twisting of the allyl moiety around the Pd-allyl axis can easily be modified by the proper choice of the nitrogen substituent. Furthermore, Pd-catalysts with ligands 1a-e provided high enantioselectivities (up to 96%) in asymmetric allylic alkylation reactions.

A great number of organic reactions catalyzed by the ionic liquid product of chlorosulfonation of 1-methylimidazole have been reported recently. At the same time controversial assumptions have appeared on the real structure of the catalyst. In the present report the primarily formed chlorosulfonation product is proved to be 1-methylimidazolium chlorosulfate ([HMim]+[SO3Cl]−) instead of 1-methyl-3-sulfonic acid imidazolium chloride, reported previously. The former structure is confirmed by X-ray crystallography and NMR spectroscopy, including 1H-, 13C-, 17O- and 15N–1H HSQC measurements. 1H and 17O NMR experiments support fast hydrolysis of [HMim] [SO3Cl] resulting in the formation of [HMim][HSO4] in the presence of traces of water.

Novel alkane-diyl based heterobidentate P,N and S,N ligands with the general formula R1R2NCH(R3)(CH2)nCH(R4)Q (R1 = Me or iPr; R2 = H or Me; R3, R4 = H or Me; n = 0, 2; Q = PPh2 or SPh) have been prepared starting from cyclic sulfate esters or naturally occurring compounds with C1 symmetry. The length of the ligands’ backbone and the reaction conditions applied strongly affected the stereochemical outcome of the synthesis when using cyclic sulfates as starting materials. Palladium(II)-complexes of the new ligands were characterized by 1D and 2D NMR spectroscopy in solution and in several cases by X-ray crystallography in the solid phase. The structural versatility of the ligands enabled the straightforward comparison of the stereoselectivity of their coordination as a function of their tether length, backbone substitution pattern, donor sets and relative carbon atom configuration in their backbone. The catalytic features of the novel compounds were investigated in asymmetric allylic alkylation reactions where the tether length proved to be a crucial factor in determining enantioselectivity.

Palladium-catalysed aminocarbonylation of aryl iodides in the presence of 2-aminobenzimidazole and 2-aminobenzoxazole as N-nucleophile was carried out. Single CO insertion took place, however, instead of the expected carboxamides (C(O)NH) the corresponding N-acyl-imine (C(O)N C) derivatives were obtained. The structure of the latter compounds can be explained by tautomerization involving the heterocyclic ring. The above structures without amide-NH moieties were proved by methylation at the NH groups of the heterocycle. The resulted mono- and dimethylated benzimidazole derivatives, as well as monomethylated benzoxazole derivatives, like the parent N-acylated compounds, were fully characterised including single crystal X-ray crystallography.

Complex formation between [Pd(en/pic)(H2O)2]2+ (en = ethylenediamine, pic = pyridine-2-methylamine) and primary hydroxamic acids (ahaH = acetohydroxamic, bhaH = benzohydroxamic acid) or secondary hydroxamic acids (meahaH = N-methyl-acetohydroxamic, pheahaH = N-phenylacetohydroxamic and phebhaH = N-phenylbenzohydroxamic acid) was studied in aqueous solution by pH-potentiometry, 1H NMR and ESI-TOF-MS. Secondary hydroxamates form 1:1 species with the [Pd(N,N)(H2O)2]2+ ions via the [O,O] chelating sets. Unexpectedly, in the primary ligands deprotonation and coordination of the hydroxamate-NH starts as low as pH

Several articles were published about the vanadate–3-hydroxy-1,2-dimethyl-pyridinone (Hdhp) system, however, the results are contradictory and not complete: pH-potentiometry and 51V NMR spectroscopy were used to clarify this complicated system. The eleven peaks in the spectra at different chemical shifts were assigned to ten stoichiometrically different compounds; four of them are new, never identified or assigned before. Besides the simple mono (in two different protonation states) and bis complexes (in three different protonation states) a tris complex, three dinuclear and a trinuclear complex were found based on the 51V NMR spectra measured at different pH values and various metal ion concentrations and metal-to-ligand ratios. As a joint evaluation of the two methods, overall stability constants were calculated for all species. X-ray structure of the potassium salt of the bis complex, [V(V)O2(dhp)2]− was also determined. The trans effect of the oxido-oxygens results in maltolato-type coordination of the ligand instead of the catecholate-like chelation. The redox properties of [V(V)O2(dhp)2]− and some other prodrug vanadium(V) bis complexes were investigated by spectrophotometry in aqueous solution via their reduction by glutathione (GSH) and l -ascorbic acid (ASC) under strictly anaerobic conditions and by cyclic voltammetry at physiological pH. The reduction was found to be much faster by ASC in all cases as compared with GSH and the reaction rate of the reduction of [V(V)O2(dhp)2]− was prominently high most probably due to the formation of the significantly higher stability of the corresponding vanadium(IV) complex.

New air-stable, water-soluble Ru(II)–phosphane complexes were synthesized in high purity by the reaction of cis-[RuCl2(dmso)4] with 2 equivalents of 1,3,5-triaza-7-phosphaadamantane (pta) and its N-methyl and N-benzyl derivatives (pta-Me and pta-Bn, respectively). All new complexes were characterized by elementary analysis and spectroscopic methods (NMR, ESI-MS) and the molecular structures of cis-cis-trans-[RuCl2(dmso)2(pta)2], cis-cis-trans-[RuCl2(dmso)2(pta-H)2]Cl2 (obtained in acidic solutions) and that of cis-cis-trans-[RuCl2(dmso)2(pta-Me)2](CF3SO3)2 were determined by single crystal X-ray diffraction. Under mild conditions, cis-[RuCl2(dmso)4] actively catalyzed the transformation of allylic alcohols into the corresponding ketones with 100% selectivity while in the same reaction the new Ru(II)–pta complexes showed moderate activity and selectivity.

Novel fused azecine ring systems were synthesized via the microwave-assisted thermal isomerization of terphenyl or biphenyl-pyridazine compounds possessing a vinyl and a tert-amino group, through application of a new extension of the tert-amino effect. Substrates for the ring closure were prepared from ortho-dihalobenzene or pyridazinone by consecutive Suzuki couplings with ortho-sec-amino- and formylphenylboronic acids, followed by Knoevenagel condensation of the aldehydes obtained.

1,3-Dioxolane- and dioxane-type (1- and 2-naphthyl)ethylidene ketals of p-methoxyphenyl α- l -rhamnopyranoside and β- d -glucopyranoside were prepared and their stereochemistry studied by solution and solid-state circular dichroism, X-ray diffraction, and coupled-oscillator CD calculations on the solid-state and MMFF-calculated geometries. Intermolecular exciton-coupled interactions between the nearby aromatic chromophores in the solid state and different conformers in solution and solid state could be identified as the main reason for the difference between solution and solid-state CDs.

The structure of tris(2,4-xylyl)phosphane (1) is reported and supramolecular assembly of gua+ salt of tris(2,4-dimethyl-5-sulfonatophenyl)phosphane co-crystal with guanidine chloride (2) is analyzed in detail. Weaving hydrogen bond ribbons with polar and apolar stabilizing pillars as well as stacking interaction of phenyl rings resulting sixfold phenyl embraces interpenetrating with the polar networks were found. Both compounds are racemate, show propeller chirality and 2 crystallizes in non-centrosymmetric space group (C3 symmetry) with the ortho-methyl groups outside of the molecular cone. According to the DFT calculations on the anion of 2, the high barrier of concerted ring rotation opens the possibility of resolving the enantiomers through hydrogen bonds to chiral donors.

Homogeneous catalytic carbonylation of some representative steroidal substrates (alkenyl iodides/enol triflates 1–5) has been carried out in the presence of (E)-1-(4′-aminophenyl)-3-ferrocenyl-prop-2-en-1-one (6) as the nucleophile. The products 1a–4a were obtained in moderate to good yield (43–75%) and were characterised with various spectroscopic methods (1H-, 13C NMR, IR, MS). The solid state structure of 17-(N-(4′-((2-ferrocenyl-ethenyl)-carbonyl)-phenyl)-carbamoyl)-5α-androst-16-ene (1a) has also been determined by X-ray crystallography.

The crystal and molecular structures of S-(2,3,4,6-tetra-O-acetyl-β- d -glucopyranosyl)-S′-(2,3,4,6-tetra-O-acetyl-β- d -galactopyranosyl)disulfide (1) and the mono-sulfoxide (3) of bis(2,3,4,6-tetra-O-acetyl-β- d -glucopyranosyl)disulfide (2) are described. Comparison of 2 and 3, containing –S–S– and –S–S(O)– bonds, respectively, allows to delineate structural differences brought about by the different oxidation states of one of the sulfur atoms in carbohydrate disulfides.

Various unsymmetrically substituted ferrocene 1,1′-diamides have been synthesized via homogeneous catalytic carbonylation starting from 1,1′-diiodoferrocene. The unique features observed in the 1H NMR and IR spectra of the compounds bearing a secondary and a tertiary amido group are explained by the formation of an internal hydrogen bond between the substituents. Addition of chloride ions (as a tetrabutylammonium salt) into the solutions of these compounds results in spectroscopic changes due to the formation of intermolecular hydrogen bonds between the ferrocene diamide and the anion. The solid state structure of 1′-(N′-butyl-carbamoyl)-morpholino ferrocenecarboxamide (1a) has also been determined by X-ray crystallography. A strong intramolecular H-bond between the NH group of the N′-butyl-carbamoyl moiety and the CO of the tertiary amido group was observed.

The first representatives of chiral boron atom-containing amine-cyanomethoxycarbonyl boranes (A · BH(CN)COOMe) have been synthesized either from the corresponding amine-bromocyanomethoxycarbonylborane complexes with [Bu4N]CN or from Me3N · BH(CN)COOMe and an amine in a base-exchange reaction. Acid hydrolyses of methyl esters generated the free acids (A · BH(CN)COOH), which are isoelectronic to the α-cyano carboxylic acids. Their pKa values and hydrolysis half-lives in acidic medium (that is rate of proton reduction) have been determined. Similarly to the alpha cyano carboxylic acids, the cyano group attached to the boron (in alpha position to the COOH group) increased the acid strength of carboxy boranes with 2.0–2.5 orders of magnitude. Independently from the type of the amine, pKa values of the amine-cyanocarboxyboranes (6.34–5.82) decrease consistently with the increase of pKb values of the amines. Hydrolytic decomposition rate of the alkylamine complexes increases with increasing pKb values of the amines while the opposite was found for pyridine base complexes. When considering both types of the amines, hydrolysis half-lives of the complexes range over several orders of magnitude from 0.005 to 400 h. Based on these observations protonation of the amine nitrogen atom appears to be the rate determining step in the hydrolysis process. With loss of methanol, 2-NH2-py · BH(CN)COOMe transformed into a five membered lactam derivative. X-ray diffraction revealed that the pyridine ring is coplanar with the five membered lactam ring. In the crystal two molecules are connected in a head to tail arrangement by strong intermolecular H-bonds between N(2)–H and the carbonyl oxygen (O1) with a donor and acceptor distance of 2.867(3) A. Three new cyanomethoxycarbonylborates having the composition of K[BHn(CN)3−nCOOMe] (n = 1, 2) and K[B(OH)(CN)2COOMe] have also been synthesized and their properties examined.

Rhodium and iridium complexes of trisulfonated triarylphosphanes, TPPTS (tris(3-sulfonatophenyl)phosphane), T(p-A)PTS (tris(3-sulfonato-4-methoxyphenyl)phosphane), T(2,4-X)TS (tris(2,4-dimethyl-5-sulfonatophenyl)phosphane), have been tested in biphasic hydrogenation of aldehydes. T(2,4-X)TS could not stabilize the rhodium complex under the applied conditions. Guanidium salt of T(2,4-X)TS has been characterized by X-ray crystallography, and Tolman cone angle of the phosphane has been determined from crystallographic data. The large cone angle (196°, 210°) explains the instability of the rhodium complex. Contrary to the T(2,4-X)TS/rhodium system, the T(2,4-X)TS/iridium catalyst has been found to be stable and effective in hydrogenation of benzaldehyde and caproaldehyde.

The complex formation between oxovanadium(IV) and 3-hydroxypicolinic acid (3HPA) was studied in aqueous solution and in the solid state. The ligand displays ambidentate binding properties [Polyhedron 19 (2000) 55]: it forms picolinate-type (N, COO−), salicylate-type (COO−, O−) and mixed-type complexes involving bidentate coordination of the ligand. It can also coordinate in a tridentate way, via the (N, COO−, O−) donor set, forming a tetrameric species. Two of complexes formed in equilibrium in solution were isolated in the solid state too: VOH2(3HPA)2 and [VO(3HPA)]4. The latter was characterized crystallographically; the binding mode was found to be identical in solution and in the solid state. The binding properties of the ligand were compared with those of other substituted picolinic acid derivatives. A possible relationship between the insulin-mimetic activity and the structure of these complexes is discussed.

Bis( N -cyclohexyl-2-pyrrolidone)dioxouranium(VI) nitrate, UO 2 (NO 3 ) 2 (NCP) 2 , has been prepared by mixing UO 2 (NO 3 ) 2 ·6H 2 O and N -cyclohexyl-2-pyrrolidone (NCP) in an aqueous nitric acid solution and characterized by NMR, IR spectroscopy, and single crystal X-ray diffractometry. The IR spectrum is consistent with typical absorption bands observed in other UO 2 (NO 3 ) 2 ·2L complexes (L=unidentate oxygen donor ligand), and supports that NCP molecule coordinates to uranium through carbonyl oxygen. The 15 N NMR spectrum shows that two structural isomers of the complex exist in inert solvents such as CD 2 Cl 2 . X-ray diffraction study reveals that average distances between uranium atom and uranyl-, nitrate-, and carbonyl- oxygen atoms are 1.748, 2.527, and 2.347 A, respectively.

α-, β- d -Gluco-, galacto-, 2-deoxy-2-phthalimido-β- d -glucopyranosides with different aglycons (methyl, allyl, p-methoxyphenyl, thioethyl) reacted with 2-naphthaldehyde dimethyl acetal to give rise to 4,6-O-(2-naphthyl)methylene acetals. The acetals were converted into fully protected compounds bearing benzoyl, benzyl, allyl, p-methoxybenzyl groups. The fully alkylated dioxane-type acetals were hydrogenolysed with AlH3 (3LiAlH4–AlCl3) reagent to furnish 4-O-NAP/6-OH derivatives. All acetals were treated with BH3·Me3N–AlCl3 in THF and a reverse regioselectivity was observed, producing 6-O-NAP/4-OH derivatives. Similar regioselectivity was also observed by using NaCNBH3–HCl reagent. In all reactions very mild reaction conditions were required, regioselectivity was better than 93:7, and the isolated yields were between 83–92%. All compounds were characterised by 1H and 13C NMR spectra. Solid-state and solution conformation of methyl 2,3-di-O-acetyl-4,6-O-(2-naphthyl)methylene-α- d -galactopyranoside were elucidated by X-ray and NMR measurements.

Acylated C-glycopyranosyl thioformamides of d -gluco, d -galacto, and d -xylo configuration were obtained by treating the corresponding glycosyl cyanides with hydrogen sulfide in the presence of triethylamine. The thioformamides gave 3,5-bis-(β- d -glycopyranosyl)-1,2,4-thiadiazoles in reactions with potassium bromate and sodium dithionite in dichloromethane–water biphasic solvent mixture. Deprotected derivatives were prepared by Zemplen deacylation.

The reaction of per-O-acetylated 1-bromo-1-deoxy-α- d -arabinopyranosyl cyanide with thiocyanate ions gave the corresponding 1-deoxy-1-thiocyanato-α- and β- d -arabinopyranosyl cyanides. In the reaction of the per-O-acetylated 1-bromo-1-deoxy-β- d -xylopyranosyl cyanide and its per-O-benzoylated β- d -glucopyranosyl analogue the corresponding 2-hydroxy-glycal esters formed in addition to the anomeric pair of thiocyanato-cyanides. The formation of 2,3,4,6-tetra-O-benzoyl-α- d -glucopyranosyl thiocyanate was demonstrated in the reaction of benzobromoglucose with thiocyanate ions. The equilibrium constant between 2,3,4,6-tetra-O-acetyl-1-deoxy-1-thiocyanato-α- and β- d -galactopyranosyl cyanides was determined. Based on this value, the equilibrium ratio for the 2,3,4,6-tetra-O-acetyl-α- and β- d -galactopyranosyl thiocyanates was calculated to be 94:6, and the anomeric effect of the SCN group was estimated to exceed 3 kcal/mol. X-Ray crystallographic data support endo- and exo-anomeric effects of the SCN moiety.

Reaction of 2,3,4,6- tetra -O- acetyl-1-bromo-1-deoxy -β- d -galactopyranosyl cyanide (4) with thiocyanate ions results in the formation of both anomers of per-O-acetylated 1-deoxy-1-thiocyanato- d -galactopyranosyl cyanides (5a and 5b). The thiocyanate group in these products is resistant to isomerization into isothiocyanate even at elevated temperatures. The X-ray structure of 5a is consistent with the operation of an exo-anomeric effect for the thiocyanate group. Compounds 5a and 5b react with hydrogen sulfide under mild conditions to yield galactopyranosylidene-spiro-thiazolidine (8) and -thiazoline (9, 12, and 13) derivatives.

The diastereoselective 1,3-dipolar cycloaddition reactions of chiral alkenes with a nitrilimine derived from d -galactose phenylhydrazone were studied. The best stereoselectivity was observed with N-acryloyl-(−)-camphor sultam 9, as the chiral inductor, to produce compound 8.

Reaction of (EE)-1-morpholino-2-methylpenta-1,3-diene 1a with dimethyl 1,2,4,5-tetrazine-3,6-di-carboxylate 2 in acetonitrile solution gives dimethyl 2,5-dimethyl-3-morpholino-8,9-diaza-tricyclo[2.2.2.02,6]oct-8-ene-1,4-dicarboxylate 4a, in high yield (79%) and with high apparent diastereoselectivity; the 1-(4-methylpiperazino) analogue 1b similarly gives compound 4b (66%). Compounds 4a and 4b are the first recorded representatives of this bridged tricyclic ring system. In contrast 2-methyl-1-morpholinocyclopentadiene 5 reacts with 2 mol. equiv. of the tetrazine 2, giving the cyclopentadipyridazine 6.

Improved methods of synthesis are reported for FcCOC 6 H 4 F-4 1a , FcCOC 6 H 4 OMe-4 1b and Fcd(COC 6 H 4 OMe-4) 2 2b [Fc = (C 5 H 5 )Fe(C 5 H 4 ); Fcd = (C 5 H 4 )Fe(C 5 H 4 )]: demethylation of 1b and 2b , using AlCl 3 in 1,1,2-trichloroethane, yields FcCOC 6 H 4 OH 1f and Fcd(COC 6 H 4 OH) 2 2f respectively. Acylation of ferrocene using 4-phthalimidobenzoyl chloride yields 4-(phthalimidobenzoyl)ferrocene 1c , hydrazinolysis of which yields FcCOC 6 H 4 NH 2 -4 1d . Crystal structures are reported for 1d, 1f and 2f : in 1d and 1f the molecules are linked into spiral chains by means of N-H ⋯ O=C and O-H ⋯ O=C hydrogen bonds respectively; in 2f the O-H ⋯ O=C hydrogen bonds link the centrosymmetric molecules into continuous two-dimensional nets, two independent sets of which are interwoven.

Reaction of mono-sulfonated triphenylphosphine in water with certain activated olefins (for example maleic acid or fumaric acid) yields the corresponding phosphonium salt under very mild conditions. This interaction promotes the formation of the catalytically active species in the hydrogenation of the olefin catalyzed by the rhodium complex of the phosphine.

Aromatic and aliphatic aldehydes can be reduced to the corresponding alcohols by hydrogen transfer from formate using, as catalysts, water-soluble complexes of Ru(II), Rh(I) and Ir(I) with monosulphonated triphenylphosphine (mSPφ)2, in aqueous/organic biphasic systems without phase transfer catalysts. HRu(O2CH)(mSPφ)2)3 was identified as the key intermediate in the processes catalyzed by RuCl2(mSPφ2)2 in an excess of phosphine. Olefinic double bonds (including those in α,β-unsaturated aldehydes), as well as substitutents of the aromatic ring, are not affected. Attempted catalysis of the transfer of benzaldehyde from the organic to the aqueous phase by β-cyclodextrin resulted in inhibition of the metal complex-catalyzed transfer hydrogenation.