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Highly substituted iodobenzenes were efficiently and regioselectively synthesized from readily available 1,6-diynes through two-step process consisting of silver-catalyzed Csp-H iodination and subsequent ruthenium-catalyzed cycloaddition of resultant iododiynes. One of the obtained p-diiodobenzenes was utilized as a halide component for cross-coupling reactions such as Mizoroki-Heck reaction, Sonogashira reaction, and Suzuki-Miyaura coupling.

Cp*RuCl-catalyzed cycloadditions of alpha, omega-diynes with electron-deficient carbon-heteroatom multiple bonds results in various heterocyclic compounds with significant chemo- and regioselectivity. The regiochemistry of these cycloadditions was successfully controlled by the steric and electronic influence of the unsymmetrical diyne substrates.

Palladium(O)-catalyzed cyclodimerization and cycloisomerizations of enyne esters is described. Uncommon six-membered ring products were predominantly formed with concomitant enyne metathesis products when enyne esters bearing a methallyl moiety were used.

The synthesis of three 4-substituted bis(oxazolinyl)pyridines and their rhodium complexes allows the study of the effect of their substituents in the catalytic asymmetric hydrosilylation of ketones. The study shows that introduction of substituents affects the critical reaction temperature at which the rhodium catalyst and silane effect smooth reduction of the ketone. Electron-withdrawing groups speed up the reaction while electron-donating groups slow it down. The substituents also enhance the enantioselectivity up to 90-94%.

Polybromoanisoles and aliphatic Grignard reagents can undergo metal-halogen exchange reaction forminghalide aromatic Grignard reagents and cyclopenta(b)benzofuran skeletons. The reaction between polybromoanisole and alkyl Grignard reagents in the presence of tetrahydrofuran exhibits the exchange of only one bromine atom that is orthoto the methoxy group. The reaction opens a new route for the study of selectiveorganic functional group conversion.

A novel four-component coupling strategy is explored to synthesize polycyclic pyrrole-2-carbohydrates. The approach comprises the relay process of the Cu-catalyzed three-component condensation giving rise to glycinate-tethered 1,6-enynes and the subsequent Ir-catalyzed cycloisomerization/Diles-Alder cycloaddition/dehydrogenative aromatization.

Highly substituted phthalides are efficiently synthesized by sequential Cp*RuCl-catalyzed cyclotrimerization of alkynylboronates, propargyl alcohols, and terminal alkynes and palladium(II) catalyzed carbonylation of the resultant arylboronates. The perfect regioselectivity of the ruthenium-catalyzed formal intermolecular cyclotrimerization is discussed on the basis of the density functional calculations of a boraruthenacycle intermediate.

A new efficient catalytic system for the highly anti-selective and enantioselective reductive aldol reaction of acrylates and aldehydes with hydrosilanes is found. It is found that Rh(Phebox) complexes act as efficient catalysts for the asymmetric conjugate reduction of alpha, beta-unsaturated esters with several hydrosilanes.

The chemo-and regioselective catalytic cyclomerization of unsymmetrical three alkyne components, by means of the temporary tethering approach with ruthenium catalysis is reported. The catalytic intermolecular cyclotrimerization of three different unsymmetrical alkynes can be accomplished with the help of ruthenium catalysis.

Halogens were used in the presence of chiral BINAP for the enantioselective SN2 displacement of hydroxy groups.

A study of novel chiral ruthenium bis(oxazolinyl)pyridine catalyst facilitates facile asymmetric cyclopropanation of olefins and diazoacetates. (RuIICl2(p-cymene))2 (1) was used as a stable precursor. 2-phenylcyclopropanecarboxylates, cis-isomer and the trans-isomer result from catalysis facilitated by the dark red solution from 1 and 2.

Investigates the nonenzymatic kinetic resolution of secondary alcohols. Enantioselective S[sub 2] displacement of hydroxy groups by halogens in the presence of chiral BINAP; Role of enantiopure alcohols for the synthesis of a wide range of natural products, chiral ligands and biologically active compounds.

Catalytic asymmetric three-component coupling reactions of terminal alkynes, α,β-unsaturated ketones, and aldehydes were studied. The chiral ruthenium complexes containing bis(oxazolinyl)phenyl ligands were found to serve as efficient catalysts for a tandem reaction based on conjugate addition of terminal alkynes to α,β-unsaturated ketones and subsequent aldol reaction with aldehydes, giving β-hydroxyketone derivatives containing α-propargyl groups in high yields with moderate to good enantioselectivities. This method can produce various functional molecules from commercially available substrates in a one-pot procedure. The absolute configuration of the major product was determined by X-ray analysis. The control experiments suggested that a ruthenium enolate species generated in situ by conjugate addition could be involved as an intermediate for the aldol coupling with an aldehyde.

Merging cooperative Si-H bond activation and electrophilic aromatic substitution paves the way for C-3-selective indole C-H functionalization under electronic and not conventional steric control. The Si-H bond is heterolytically split by the Ru-S bond of a coordinatively unsaturated cationic ruthenium(II) complex, forming a sulfur-stabilized silicon electrophile. The Wheland intermediate of the subsequent Friedel-Crafts-type process is assumed to be deprotonated by the sulfur atom, no added base required. The overall catalysis proceeds without solvent at low temperature, only liberating dihydrogen.

Propargylic alcohols were obtained with excellent enantioselectivities in the asymmetric direct alkynylation of aldehydes using 5 mol % of chiral ruthenium complexes containing the chiral bis(oxazolinyl)phenyl ligand.

The intermolecular reductive coupling reaction of cyclopent-2-enone and aromatic aldehydes was realized by chiral rhodium-(bisoxazolinyl)phenyl catalysts, Rh(Phebox-Ph)(OAc)(2)(H(2)O), with diphenymethylsilane as a hydride donor to give the corresponding beta-hydroxyketones in high anti-selectivity (up to 96%) with high enantioselectivity (up to 93%).

[reaction: see text] The conjugate reduction of cinnamates with hydrosilane and chiral Rh(Phebox-ip) catalyst in the presence of excess acetone is shown to provide the corresponding intermolecular reductive aldol product in extremely high enantioselectivity (up to 98%). Several cinnamates and crotonate substrates and several ketone acceptors were also examined.

[reaction: see text] Spirocyclic C-arylribosides were synthesized from the known gamma-ribonolactone derivative. Lithium acetylide addition followed by glycosylation with 3-(trimethylsilyl)propargyl alcohol converted the ribonolactone to silylated diynes. After desilylation or iodination, subsequent ruthenium-catalyzed cycloaddition of resultant diynes with alkynes or chloroacetonitrile gave spirocyclic C-arylribosides.

In the presence of a catalytic amount of Cp*RuCl(cod), 1,6-diynes were allowed to react chemo- and regioselectively with electron-deficient nitriles and heterocumulenes at 60-90 degrees C to afford heterocyclic compounds. The mechanism of the ruthenium-catalyzed regioselective formations of bicyclic pyridines and pyridones were analyzed on the basis of density functional calculations. Cyclocotrimerizations of ethyl propiolate with ethyl cyanoformate or propyl isocyanate gave rise to two of the four possible pyridine or pyridone regioisomers.