74395-08-7

The present invention relates to a method for preparing a cyclic ketone derivative with an increased carbon number by performing a ring expansion reaction of a β-selenyl cyclic ketone derivative. The present invention was first developed by performing the

C2-symmetric chiral diene ligands based on 4,8-endo,endo-disubstituted bicyclo[3.3.1]nona-2,6-diene framework have been designed and synthesized. The rhodium complexes of the dienes, which were obtained in a few straightforward steps from enantiomerically pure bicyclo[3.3.1]nonane-2,6-dione, exhibited excellent catalytic activity and high enantioselectivity (up to 96% ee) in the conjugate addition reaction of arylboronic acids to cyclic enones under mild reaction conditions with high atom efficiency. Chiral C2-symmetric 4,8-endo,endo-disubstituted bicyclo[3.3.1]nona-2,6-diene ligands were synthesized from easily available bicyclo[3.3.1]nonane-2,6-dione and utilized in the asymmetric 1,4-addition reaction of arylboronic acids to cyclic enones. The catalyst prepared in situ from ligand 4b and [RhCl(C2H4)2]2 exhibited excellent catalytic activity and high enantioselectivity (up to 96% ee) under mild reaction conditions with high atom efficiency.

An air- and water-stable CCC-NHC pincer Rh complex catalyzed the 1,4-addition of aryl boronic acids to α,β-unsaturated ketones and aldehydes. This bench top method proceeds in eco-friendly solvents including methanol and water. The scope of boronic acids was expanded to include heterocyclic examples.

Teaching new tricks to an old dog: By intercepting adducts between ketones and lithium trimethylsilyldiazomethane, a new Tiffeneau-Demjanov type methylene homologation could be realized in a single-step operation. Among proton sources and Lewis acids, silica gel was found to be the most effective reagent for the protonation of intermediates and their subsequent ring expansion (see scheme). Copyright

The rhodium-catalysed enantioselective 1,4-addition of organoboron reagents to arylidene Meldrum's acids as acceptors, allows convenient access to 4-arylchroman-2-ones with good to excellent levels of enantioselectivity. The use of silyl-protected dioxabo

The complex RhCl(COD){3-benzyl-1-(2-hydroxy-2-phenylethyl)imidazol-2- ylidene} has been prepared by reaction of the dimer [Rh(μ-OMe)(COD)] 2 with 3-benzyl-1-(2-hydroxy-2-phenylethyl)imidazolium chloride and characterized by X-ray diffraction analysis. The structure reveals that 75% of the molecules are associated through intermolecular O-H...Cl hydrogen bonds between the OH group of the NHC substituent of one molecule and the chloride ligand of the adjacent molecule. This complex catalyzes the addition of arylboronic acids to cyclic and acyclic enones in anhydrous toluene. The alcohol function of the substituent of the NHC ligand plays the role assigned to water in previous cases.

A novel rhodium-catalyzed conjugate addition of indium reagents to electron deficient olefins is reported. The reaction takes place in THF/MeOH at 110 °C using arylindium dichlorides, a rhodium(I)-binap complex as catalyst, and α,β-unsaturated ketones and

Testing the waters: An architecture-based system for transition-metal catalysis consisting of a self-assembled amphiphilic pincer palladium complex bearing hydrophilic and hydrophobic chains has been developed. Self-assembly of the bilayer vesicles of the complex, concentration of the organic substrates within the hydrophobic region of the bilayer membrane, and catalytic transformation of the substrate all occur sequentially in water (see scheme). Copyright

A robust and practical polymer-supported, homogeneous, recyclable biphephos rhodium(I) catalyst has been developed for C-C bond formation reactions. Control of polymer molecular weight allowed tuning of the polymer solubility such that the polymer-supported catalyst is soluble in nonpolar solvents and insoluble in polar solvents. Using the supported rhodium catalysts, addition of aryl and vinylboronic acids to the electrophiles such as enones, aldehydes, N-sulfonyl aldimines, and alkynes occurs smoothly to provide products in high yields. Additions of terminal alkynes to enones and industrially relevant hydroformylation reactions have also been successfully carried out. Studies show that the leaching of Rh from the polymer support is low and catalyst recycle can be achieved by simple precipitation and filtration.

The Pd-catalysed conjugate addition of arylboronic acids to α,β-unsaturated cyclic ketones was studied under controlled microwave irradiation conditions. A variety of catalysts, bases and solvents was explored in order to achieve optimum yields in the sho

The synthesis and catalytic activity of three well-defined monomeric rhodium(i) hydroxide complexes bearing N-heterocyclic carbene (NHC) ligands are reported. [Rh(cod)(ICy)(OH)] promoted the 1,4-addition of arylboronic acids to cyclic enones, with TONs an

Figure presented Axially chiral cis-chelated bidentate bis(N-heterocyclic carbene)-palladium(II) complexes are effective catalysts for the asymmetric conjugate addition of arylboronic acids to 2,3-dihydro-4-pyridones, producing the synthetically and biolo

Arylboronic acids react with aldehydes and α,β-unsaturated carbonyl compounds in the presence of a base and a catalytic amount of a palladium(0) complex with chloroform, affording the corresponding addition products in good yields, and chiral benzhydrol was obtained with up to 43% e.e. using (S,S)-bppm as a ligand. General palladium complexes have no catalytic activity without chloroform. Because chloroform is essential for this reaction, these reactions would be promoted by dichloromethylpalladium(II) species.

A robust and practical polymer-supported, recyclable biphephos rhodium(l) catalyst has been developed. Control of polymer molecular weight allowed the tuning of solubility such that the polymer-supported catalyst is soluble in nonpolar solvents and not soluble in polar solvents. Thus, catalytic addition of aryl- and vinylboronic acids to enones occurs under completely homogeneous conditions and catalyst recycle can be achieved by simple precipitation and filtration.

Platinum salts represented by K2PtCl4 were found to catalyze the 1,4-addition of arylboronic acids to β-substituted α,β-unsaturated ketones to give high yields of β-arylated ketones. The reaction is completed in 1h in the presence of 1 mol % of the catalyst in dioxane/H2O at 70 °C. Copyright

Stable and reusable tetraorganosilicon reagents, alkenyl-, aryl-, and silyl[2-(hydroxymethyl)phenyl]-dimethylsilanes, undergo 1,4-addition reactions to α,β-unsaturated carbonyl acceptors under mild rhodium-catalysis. The reaction tolerates a diverse range of functional groups and is applicable to gram-scale synthesis. Use of a chiral diene ligand allows the achievement of the corresponding enantioselective transformations using the tetraorganosilicon reagents, providing the silicon-based approach to optically active ketones and substituted piperidones that serve as synthetic intermediates of pharmaceuticals. A rhodium alkoxide species is suggested to be responsible for a transmetalation step on the basis of the observed kinetic resolution of a racemic chiral phenylsilane in the enantioselective 1,4-addition reaction under the rhodium-chiral diene catalysis.

A library of 19 chiral tropos phosphorus ligands, based on a free-to-rotate (tropos) biphenol unit and a chiral P-bonded alcohol (11 phosphites, 1-P(O)2O to 11-P(O)2O) or secondary amine (8 phosphoramidites, 12-P(O)2N to 19-P(O)2N). were screened, individually and in combinations of two, in the rhodium-catalyzed asymmetric conjugate addition of arylboronic acids to enones and enoates. High enantioselectivities (up to 99% ee) and excellent yields were obtained in the addition to either cyclic or acyclic substrates. The flexible biphenolic P ligands outperformed the analogous rigid binaphtholic P ligands. Variable-temperature 31P NMR studies revealed that the biphenolic ligands are tropos even at low temperature. Only below 190 K was a coalescence observed: upon further cooling, two atropisomers were detected. The Rh homocomplexes ([Rh(La)2]+) were also studied: in general, a single doublet (P-Rh coupling) was observed in the case of the biphenolic phosphite ligands, over the temperature range 380-230 K, demonstrating their tropos nature in the rhodium complexes even at low temperatures. On the other hand, the phosphoramidites showed different behaviors depending on the structure of the ligand and on the nature of the rhodium source. The spectrum at 230 K of the mixture of [Rh(acac)(eth)2] (eth = C2H4) with phosphite 6-P(O)2O and phosphoramidite 19-P(O)2N (the most enantioselective ligand combination in the conjugate addition reaction) revealed the presence of four homocomplexes (total approximately 40%: [Rh(6-P(O)2}2], [Rh{(aR)-19-P(O)2N}2], [Rh((aS)-19-P(O)2N) 2], [Rh((aR)-19-P(O)2N}((aS)-19-P(O)2N}]) and one heterocomplex, [Rh{6-P(O)2O){(aR)-19-P(O)2NJ] (approximately 60%) In the heterocomplex, the biphenol-derived phosphite is free to rotate (tropos) while the biphenol-derived phosphoramidite shows a temperature-dependent tropos/atropos behavior (coalescence temperature = 310 K).

1,4-Addition of arylboronic acids to α,β-unsaturated ketones was smoothly catalyzed by palladium(0) phosphine complexes with chloroform in the presence of base. It is remarked that the palladium(0) complexes have no catalytic activity in the absence of chloroform. The reaction proceeded without β-hydride elimination. Copyright

Diarylindium(III) hydroxides react with α,β-unsaturated carbonyl compounds in the presence of a rhodium catalyst to afford the 1,4-addition products in high yield. This reaction demonstrates the utility of diarylindium(III) hydroxide as an aryl source with rhodium catalysts. The Royal Society of Chemistry 2005.

The addition of aryltrialkoxysilanes to α,β-unsaturated carbonyl compounds (ketones, aldehydes) and nitroalkenes in the presence of SbCl3, TBAF, AcOH, and a catalytic amount of Pd(OAc)2, in CH3CN at 60 °C, provides the corresponding conjugate addition products in moderate to good yields. The addition of equimolar amounts of SbCl3 and TBAF is necessary for this reaction to proceed smoothly. The arylpalladium complex, which is generated by the transmetalation from a putative hypercoordinate silicon compound, is considered to be the catalytically active species.

Process for the preparation of enantiomerically enriched compounds with formula Ar - C(R1) - C(R2) - Z wherein Ar represents an optionally substituted (hetero)aryl group, R1 and R2, each independen tly, represen

Catalytic 1,4-addition of arylsiloxanes to enones was carried out at 75°C in the presence of a dicationic palladium(II) catalyst in aqueous 1,4-dioxane. A nitrile-free complex generated in situ from Pd(dba)2 and Cu(BF4)2 in the presence of dppe or dppben was recognized to be the best catalyst to achieve high yields for the representative enones and enals.

A cationic palladium complex was found to be an efficient catalyst for the 1,4-addition of aryl boronic acids to enones at room temperature (see scheme; X= ClO4, OTf, BF4, PF6, or SbF6); Tf=trifluoromethanesulfonyl).

Process for the preparation of enantiomerically enriched compounds with Formula Ar-C(R1)-C(R2)-Z wherein Ar represents an optionally substituted (hetero)aryl group, R1 and R2, each independently, represent H, an alkyl, (hetero)aryl, dialkylamino, amido, thioether, alkoxy or aryloxy group with the proviso that not both R1 and R2 represent H, or R1 and R2 form together with the C-atoms to which they are bound a (hetero)alkyl or (hetero) alkenyl ring and Z represents an electron withdrawing group, in which process a boronic acid derivate of Formula Ar-B(OR3)OR4 or its anhydride, wherein Ar is as described above and R3 and R4, each independently, represent H or an alkyl group, is reacted with an olefinic unsaturated compound with Formula R2 - C = C - (R1)Z, wherein R1, R2 and Z are as described above, in the presence of a transition metal catalyst comprising a transition metal chosen from Cu and group VIII of the Periodic Table and an enantiomerically enriched ligand L, having the Formula (I) where Cn together with the two O-atoms and the P-atom forms a substituted or non-substituted ring with 2-6 C-atoms, R5 and R6 each independently stand for H, an optionally substituted alkyl, aryl, alkaryl, or aralkyl group, or represent the group with Formula (II) wherein Cn1 may have the same meanings as given for Cn and B represents a bridging group, or R5 and R6 may form a heterocyclic ring together with the N-atom to which they are bound.

Potassium organotrifluoroborates, highly stable organoboron derivatives, participate in asymmetric 1,4-additions to enones. This reaction, catalyzed by cationic rhodium(I) complexes chelated with binap, MeO-biphep or josiphos ligand, affords 1,4-adducts w

ArSiCl3 and Ar2SiCl2, believed to be unstable in aqueous media, reacted efficiently with α,β-unsaturated ketones and esters in air and water (in the presence of sodium fluoride and a rhodium catalyst), giving good to excellent yields of the desired conjugate addition products.

Intramolecular coupling occurs when cyclic α-(bromomethyl) β-keto esters are electrochemically reduced in the presence of trimethylsilyl chloride and one-carbon ring-enlarged products are obtained in reasonable yields.Electroreduction of α-(γ-bromopropyl) β-keto esters also affords the corresponding five-membered cyclized products and/or the corresponding ring-opened compounds.The ease of ring opening of the cyclized products is highly influenced by their stereoconfiguration.Electroreduction of α-(β-bromoethyl) β-keto ester gives the product formed by the reductive elimination of the bromoethyl group whereas α-(δ-bromobutyl) β-keto ester yields the product of the reductive elimination of bromine.This electroreductive intramolecular coupling is initiated by the reduction of the carbon-bromine bond and proceeds through a carbanion intermediate.

The palladium(0) catalyzed reactions of arylazo aryl sulfones (1) with α,β-unsaturated esters in benzene give aryl-substituted esters as major products and hydroarylated esters as minor products.The reactions of 1 with acyclic α,β-unsaturated ketones give considerable amounts of hydroarylated ketones and aryl-substituted ketones under similar conditions, whereas the reactions of 1 with cyclic α,β-unsaturated ketones afforded selectively hydroarylated compounds and no formation of aryl-substituted ketones was found.A plausible reaction mechanism is proposed.Key words: Arylazo aryl sulfones; palladium(0) catalyst; arylation; α,β-unsaturated carbonyl compounds; diarylpalladiumII) intermediate; catalytic cycle.

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