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• 25935-97-1 6-methyl-2,3-diphenylbenzo[b]thiophene 
• 70603-14-4 (1-(p-tolyl)ethene-1,2-diyl)dibenzene 
• 103-30-0 (E)-1,2-diphenyl-ethene 
• 108-88-3 toluene 
• 645-49-8 cis-stilben 
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• 76-03-9 trichloroacetic acid 
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• 84224-84-0 α-(3-Methylphenylsulfenyl)benzyl-phenyl-keton 

Relevant academic research and scientific papers

Nickel-Catalyzed Asymmetric Reductive Diarylation of Vinylarenes

A nickel-catalyzed asymmetric diarylation reaction of vinylarenes enables the preparation of chiral α,α,β-triarylated ethane scaffolds, which exist in a number of biologically active molecules. The use of reducing conditions with aryl bromides as coupling partners obviates the need for stoichiometric organometallic reagents and tolerates a broad range of functional groups. The application of an N-oxyl radical as a ligand to a nickel catalyst represents a novel approach to facilitate nickel-catalyzed cross-coupling reactions.

Pd-Catalyzed reductive heck reaction of olefins with aryl bromides for Csp2-Csp3 bond formation

We developed a Pd-catalyzed intermolecular reductive Heck reaction to construct Csp2-Csp3 bonds between aryl bromides and olefins. Various styrene derivatives, acyclic and cyclic alkenes, were well tolerated to couple with varied aryl bromides in linear selectivity. Kinetic and deuterium labeling experiments suggested that i-PrOH provides a hydride through β-H elimination.

Iridium-catalyzed asymmetric hydrogenation yielding chiral diarylmethines with weakly coordinating or noncoordinating substituents

Diarylmethine-containing stereocenters are present in pharmaceuticals and natural products, making the synthetic methods that form these chiral centers are important in industry. We have applied iridium complexes with novel N,P-chelating ligands to the asymmetric hydrogenation of trisubstituted olefins, forming diarylmethine chiral centers in high conversions and excellent enantioselectivities (up to 99% ee) for a broad range of substrates. Our results support the hypothesis that steric hindrance in one specific area of the catalyst is playing a key role in stereoselection, as the hydrogenation of substrates differing little at the prochiral carbon occurred with high enantioselectivity. As a result, excellent stereodiscrimination was obtained even when the prochiral carbon bore, for example, phenyl and p-tolyl groups.

Alkene Hydrofunctionalization Reactions

A reductive cross coupling reaction process for functionalization of a nucleophilic alkene can be achieved. The nucleophilic alkene and a nucleophilic cross coupling partner compound can be reacted in the presence of an oxidizable alcohol and a suitable catalyst to form a reductive coupling product. Various additives can also be useful to refine the process such as by mitigating certain undesirable intermediates, facilitating specific site selectivity for various substitutions or reaction sites, etc. Chiral additives can be optionally used which act to provide asymmetric catalysis, e.g. allow for regioselective and stereoselective production of reductive coupling products. A reductive cross coupling pathway can include oxidizing the oxidizable alcohol to form a catalyst hydride. The nucleophilic alkene can be inserted into the catalyst hydride to form a catalyst-alkyl intermediate. Further, the catalyst-alkyl intermediate can be transmetallized with the nucleophilic cross coupling partner compound to form a transmetallated intermediate. The catalyst can be reductively eliminated to form the reductive coupling product and a reduced catalyst. Finally, the reduced catalyst can be oxidized under aerobic conditions, for example with oxygen, to form the oxidized catalyst and subsequent repetition through the cyclic pathway.

A new approach to carbon-carbon bond formation: development of aerobic Pd-catalyzed reductive coupling reactions of organometallic reagents and styrenes

Alkenes are attractive starting materials for organic synthesis and the development of new selective functionalization reactions is desired. Previously, our laboratory discovered a unique Pd-catalyzed hydroalkoxylation reaction of styrenes containing a phenol. Based upon deuterium labeling experiments, a mechanism involving an aerobic alcohol oxidation coupled to alkene functionalization was proposed. These results inspired the development of a new Pd-catalyzed reductive coupling reaction of alkenes and organometallic reagents that generates a new carbon-carbon bond. Optimization of the conditions for the coupling of both organostannanes and organoboronic esters is described and the initial scope of the transformation is presented. Additionally, several mechanistic experiments are outlined and support the rationale for the development of the reaction based upon coupling alcohol oxidation to alkene functionalization.

Detailed Characterization of p-Toluenesulfonic Acid Monohydrate as a Convenient, Recoverable, Safe, and Selective Catalyst for Alkylation of the Aromatic Nucleus

Alkylation of the aromatic nucleus, an important reaction in industry and synthetic organic chemistry, has traditionally been carried out by the well-known Friedel-Crafts reaction employing Lewis acid catalysts such as AlCl3 and BF3 or by using highly reactive organometallic reagents. Although protic acids such as anhydrous HF and concentrated H2SO4 have also been used in the alkylation of the aromatic nucleus, the notoriously corrosive, highly toxic, and hazardous nature of these agents has precluded their common use under ordinary laboratory conditions. Various organic sulfonic acids have, on occasion, been used as catalysts in Friedel-Crafts alkylations, but to our knowledge the chemistry and the scope of these reactions for common laboratory use have never been exploited in detail. In the present study we have characterized commercially available p-toluenesulfonic acid monohydrate (TsOH) as an efficient catalyst for the intermolecular coupling of the aromatic nucleus with activated alkyl halides, alkenes, or tosylates under mild conditions in an open atmosphere. In comparison to conventional Friedel-Crafts catalysts such as AlCl3, BF3, HF, and concentrated H2SO4, the extent of the formation of undesired products from side reactions such as transalkylation, polymerization, etc. was minimal with the TsOH-catalyzed reaction. The ability to recover and reuse the catalyst from the reaction mixtures, minimal generation of environmentally unfriendly waste, high specificity of the reaction, and the low cost of the catalyst are important advantages of the TsOH catalyst over the other conventional Friedel-Crafts catalysts.

The reaction of hydrogallium(III) dichloride (HGaCl2) with olefines, acetylenes, and α,β-unsaturated ketones

The reaction of HGaCl2 with 1-octene yields 1-octylgallium(III) dichloride in 77percent yield, but with 2-octene a 2:1 mixture of 2- and 3-octylgallium dichloride(III) is obtained in 88percent yield, and the reaction of (E)-stilbene gives an even more complex mixture.Hydrogallation of 1,4-diphenylbutadiene with HGaCl2 followed by hydrolysis yields 1,4-diphenylbutane in 53percent yield.The reactions of diphenylacetylene and 4-octyne under the same conditions give (E)-stilbene and (E)-4-octene in 76percent and 63percent yield, respectively, while 1-octyne undergoes polymerization. 2-Benzoylstyrene (calcone) reacts with HGaCl2 to give, as the main product, a compound arising from 1,4-addition of the H-Ga bond across the enone system, together with a double hydrogallation product.

Synthesis and Reactions of Sulfenic Trifluoromethanesulfonic Anhydrides

Sulfenyl halogenides 1 and 4 react with silver trifluoromethanesulfonate (2) to give aryl 3 and alkylsulfenic trifluoromethanesulfonic anhydrides 5, resp., in good yields; 3 and 5 could not be isolated because of their instability. 1H NMR spectroscopic data of 5a, b, each in dichloromethane and nitromethane, resp., are indicative of a dissoziation to adducts of alkylsulfenylium ions and the solvent.Whereas 3 do not react with aromatic compounds, addition products with diphenylacetylene, arylsulfenylvinyl trifluoromethanesulfonates 11, are formed smoothly, which under the reaction conditions immediately cyclize to give benzothiophenes 10 in excellent yields.