Yasuo Hatanaka

Palladium-catalyzed cross-coupling reaction of organometalloids through activation with fluoride ion

Activation of organosilicon compounds with fluoride ion produces a transient pentacoordinate silicate, which is capable of transmetalation with a catalytic organopalladium complex and achieves cross-coupling reaction. Mono-, di- or trifluorosilanes can deliver alkenyl, aryl, or alkyl group, respectively. The reaction, characterized by high chemo- and stereoselectivity, was successfully applied to synthesis of HMG-CoA reductase inhibitor NK-104 and functionalized biaryls for liquid crystals. The stereochemical aspects are discussed.

NaOH-Promoted cross-coupling reactions of organosilicon compounds with organic halides: Practical routes to biaryls, alkenylarenes and conjugated dienes

Abstract The use of NaOH has been found to be extremely effective in promoting the palladium-catalyzed cross-coupling reactions of aryl and alkenylchlorosilanes with organic halides such as aryl bromides and chlorides under very mild conditions.

Carbonylative coupling reaction of organofluorosilanes with organic halides promoted by fluoride ion and palldium catalyst

Abstract Palladium-catalyzed carbonylative cross coupling reaction of organofluorosilanes with organic halides was achieved in the presence of fluoride ion and an atmospheric pressure of carbon monoxide. Alkenyl- or arylfluorosilanes effectively underwent this reaction with alkenyl or aryl iodides in moderate to good yields. Thus, highly functionalized ketones are readily available without protection of reactive functional group such as aldehyde, ketone, ester, nitrile, and alcohol. For smooth ketone formation, use of organofluorosilanes is essential; tetraorganosilanes like aryl(trimethyl)silanes, upon reaction with aryl iodides, gave aroyl fluorides instead.

Highly selective cross-coupling reactions of aryl(halo)silanes with aryl halides: A general and practical route to functionalized biaryls

Abstract The palladium catalyzed cross-coupling reaction of aryl halides with aryl(halo)silanes (halogen=F, Cl) gives good yields of unsymmetrical biarlys and p

A wide range of organosilicon compounds couples with enol and aryl triflates in the presence of Pd catalyst and fluoride ion

Abstract Under the influence of tetrakis(triphenylphosphine)palladium and tetrabutylammonium fluoride, the title reaction took place with alkenyl, alkynyl, aryl, and alkylsilanes to give the corresponding coupled products in good yields with high chemoselectivity and stereospecificity.

A one-pot synthesis of conjugated dienynes by palladium-mediated three component cross-coupling reaction

Abstract Palladium-catalyzed one-pot sequential reaction of Me 3 SnC≡CSiMe 3 first with an alkenyl iodide R 1 I and secondly with another alkenyl (or aryl) iodide R 2 I in the presence of newly added (Et 2 N) 3 S + Me 3 SiF 2 − affords conjugated dienynes R 1 -C≡C-R 2 with high stereospecificity.

On the regioselectivity of palladium catalyzed cross-coupling reactions of alkenylsilanes: Participation of β-cationic organosilicate-palladium species during the transmetallation

Abstract The cross-coupling reaction promoted by a palladium catalyst and fluoride salt of 1-[(fluoro)(dimethyl)silyl]-1-phenylethene ( 1 ) with substituted aryl iodides gave the unexpected cine -substitution products ( E )-1-aryl-2-phenylethenes ( 3 ) along with the normal ipso -substitution product 1-aryl-1-phenylethene ( 2 ). The product ratios were strongly dependent on the electronic nature of the substituent on aryl iodides: ipso -substitution products ( 2 ) were favoured by an electron-withdrawing substituent, and cine -substitution products ( 3 ) by an electron-donating substituent. On the basis of these observations, the following mechanism of transmetallation of alkenyl(fluoro)silicates with arylpalladium is proposed: electrophilic attack of an arylpalladium complex on the olefinic α-carbon of an alkenyl(fluoro)silicate produces a β-cationic organosilicate-palladium species which then transfers the alkenyl group from silicon to the palladium complex.

Pentacoordinate organosilicate as an alkylating reagent: Palladium catalyzed methylation of aryl halides

Abstract Under the influence of palladium catalyst, tris(diethylamino)sulfonium difluorotrimethylsilicate is found to deliver the methyl group to aryl halides highly chemoselectively, and the corresponding methylated aromatic compounds are produced in moderate to high yields.

Regio- and stereoselective cross-coupling reaction of optically active allylsilanes: Stereocontrol of palladium-mediated SE′ reactions

Abstract Optically active allylsilanes undergo the γ-regioselective cross-coupling reactions with aryl triflates in the presence of a palladium catalyst and a fluoride salt; the absolute configuration and % ee of the coupled products could be controlled by the choice of the fluoride salt and the polarity of the solvent.

Palladium catalyzed cross-coupling reaction of functionalized alkyltrifluorosilanes with aryl halides

Abstract A variety of alkyltrifluorosilanes were found to couple with aryl halides in the presence of Pd(PPh3)4 catalyst and tetrabutylammonium fluoride (TBAF) to give the corresponding cross-coupled products in moderate to good yields.