Facile synthesis of 1,2-aminoalcohols α-C-H aminoalkylation of alcohols by photoinduced hydrogen-atom transfer catalysis.

1,2-Aminoalcohols are common motifs found in a wide range of natural products and pharmaceutical compounds. Here we report a photocatalytic method for the direct conversion of readily available aliphatic alcohols into synthetically valuable 1,2-aminoalcohols. A dual catalytic system consisting of an acridinium photoredox catalyst and a cationic hydrogen-atom transfer (HAT) catalyst based on 1,4-diazabicyclo[2.

Catalytic direct hydrocarboxylation of styrenes with CO and H.

A three-component hydrocarboxylation of an olefin with CO and H could be regarded as a dream reaction, since it would provide a straightforward approach for the synthesis of aliphatic carboxylic acids in perfect atom economy. However, this transformation has not been realized in a direct manner under mild conditions, because boosting the carboxylation with thermodynamically stable CO while suppressing the rapid hydrogenation of olefin remains a challenging task. Here, we report a rhodium-catalysed reductive hydrocarboxylation of styrene derivatives with CO and H under mild conditions, in which H served as the terminal reductant.

Rhodium-Catalyzed meta-Selective C-H Carboxylation Reaction of 1,1-Diarylethylenes via Hydrorhodation-Rhodium Migration.

A meta-selective C-H carboxylation reaction of 1,1-diarylethylene derivatives with CO by using a rhodium catalyst with NaO Pr as a stoichiometric reductant has been achieved. Together with hydrogenation of the ethylene moiety, a carboxyl group was introduced to the meta-position of the aryl ring with high selectivity over the ortho-positions. Experimental and computational mechanistic studies indicate that this carboxylation reaction proceeds via hydrorhodation on the ethylene moiety, followed by 1,4-rhodium migration and successive 1,2-rhodium migration on the aryl ring.

Palladium-Catalyzed Visible-Light-Driven Carboxylation of Aryl and Alkenyl Triflates by Using Photoredox Catalysts.

A visible-light-driven carboxylation of aryl and alkenyl triflates with CO is developed by using a combination of Pd and photoredox catalysts. This reaction proceeds under mild conditions and can be applied to a wide range of substrates including acyclic alkenyl triflates.

Photocatalytic Transfer Hydrogenolysis of Allylic Alcohols on Pd/TiO : A Shortcut to (S)-(+)-Lavandulol.

We report herein a regio- and stereoselective photocatalytic hydrogenolysis of allylic alcohols to form unsaturated hydrocarbons employing a palladium(II)-loaded titanium oxide; the reaction proceeds at room temperature under light irradiation without stoichiometric generation of salt wastes. Olefin and saturated alcohol moieties tolerated the reaction conditions. Hydrogen atoms were selectively incorporated into less sterically congested carbons of the allylic functionalities.

N-methylation of amines with methanol at room temperature.

N-Methylation of amines with methanol proceeds at room temperature in the presence of a silver-loaded titanium dioxide (Ag/TiO2) photocatalyst under UV-vis light irradiation. This method allows facile synthesis/isolation of N-methylamines bearing various functional groups including N-benzyl, N-allyl, N-Boc, hydroxyl, ether, acetal, carboxamide, formamide, and olefin groups.

Nucleophile-catalyzed additions to activated triple bonds. Protection of lactams, imides, and nucleosides with MocVinyl and related groups.

Additions of lactams, imides, (S)-4-benzyl-1,3-oxazolidin-2-one, 2-pyridone, pyrimidine-2,4-diones (AZT derivatives), or inosines to the electron-deficient triple bonds of methyl propynoate, tert-butyl propynoate, 3-butyn-2-one, N-propynoylmorpholine, or N-methoxy-N-methylpropynamide in the presence of many potential catalysts were examined. DABCO and, second, DMAP appeared to be the best (highest reaction rates and E/Z ratios), while RuCl3, RuClCp*(PPh3)2, AuCl, AuCl(PPh3), CuI, and Cu2(OTf)2 were incapable of catalyzing such additions. The groups incorporated (for example, the 2-(methoxycarbonyl)ethenyl group that we name MocVinyl) serve as protecting groups for the above-mentioned heterocyclic CONH or CONHCO moieties.

(15)N Double-labeled guanosine from inosine through ring-opening-ring-closing and one-pot Pd-catalyzed C-O and C-N cross-coupling reactions.

[N,1-(15)N(2)]-Guanosine, or [1,NH(2)-(15)N(2)]-guanosine, and derivatives were prepared from tri-O-acetylinosine, via N-nitration and reaction with (15)NH(2)OH, followed by conversion of the (15)N-labeled 1-hydroxyinosine to the corresponding 2,6-dichloropurine riboside. The sequential one-pot C-O and C-N key couplings of this dichloro derivative with PhCH(2)OH and PhCO(15)NH(2) or (i)PrCO(15)NH(2) was achieved in good overall yields, with Pd(0)-Xantphos as the best choice of five different catalytic systems examined.