Masahiro Miura 교수

Aromatic substrates with oxygen- and nitrogen-containing substituents undergo oxidative coupling with alkynes and alkenes under rhodium catalysis through regioselective C-H bond cleavage. Coordination of the substituents to the rhodium center is the key to activate the C-H bonds effectively. Various fused-ring systems can be constructed through these reactions.

Not only monoarylation but also diarylation of 2-phenylphenols with aryl iodides proceeds effectively and regioselectively when a palladium catalyst and an appropriate base are employed. The products are 1,2-diphenyl- and 1,2,3-triphenylbenzene derivatives, respectively (see below). Also discussed is the arylation of 1- and 2-naphthols. X = H, OMe; Y = H, Me; Z = H, OMe, NO2.

The rhodium-catalyzed oxidative coupling of aromatic imines with alkynes effectively proceeds via regioselective C-H bond cleavage to produce indenone imine and isoquinoline derivatives.

Playing Reversi with H and N: A copper-catalyzed intermolecular regioselective hydroamination of styrenes with polymethylhydrosiloxane and hydroxylamine derivatives has been developed. The catalysis accommodates challenging β-substituted substrates. Moreover, the chiral biphosphine-ligated copper complex successfully forms benzylamines with good enantiomeric ratios.

N-(2‘-Phenylphenyl)benzenesulfonamides react with acrylate esters accompanied via cleavage of the C−H bond at their 2‘-position in the presence of a catalyst system of Pd(OAc)2 and Cu(OAc)2 and a base under air to produce 5,6-dihydro-5-(benzenesulfonyl)phenanthridine-6-acetate derivatives in high yields. The reactions of benzoic acid with butyl acrylate and styrene can also give 3-[(butoxycarbonyl)methyl]phthalide and 3-phenylisocoumarin, respectively.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCopper-Catalyzed Reaction of Terminal Alkynes with Nitrones. Selective Synthesis of 1-Aza-1-buten-3-yne and 2-Azetidinone DerivativesMasahiro Miura, Masahiro Enna, Kazumi Okuro, and Masakatsu NomuraCite this: J. Org. Chem. 1995, 60, 16, 4999–5004Publication Date (Print):August 1, 1995Publication History Published online1 May 2002Published inissue 1 August 1995https://pubs.acs.org/doi/10.1021/jo00121a018https://doi.org/10.1021/jo00121a018research-articl

Breaking the Si-lence: The direct cross-coupling of heteroarenes with aryl- or alkenylsilanes proceeds efficiently, in the presence of a nickel catalyst, to create a wide range of aryl–and alkenyl–heteroaryl bonds efficiently (see scheme; DMAc=N,N-dimethylacetamide, bpy=2,2′-bipyridine). This catalysis represents a new avenue for using organosilanes in the catalytic CH functionalization chemistry.

Hot couple: A precious-metal-free copper-mediated intermolecular direct biaryl coupling of benzoic acid derivatives and 1,3-azoles has been developed. The key to success is the installation of an amide-based bidentate coordinating group, which is easily removed and transformed into the parent ester groups after the coupling reaction. Kinetic studies indicate that the rate-limiting step is the aromatic CH bond cleavage of benzoic acid derivatives. As a service to our authors and readers, this jo

Designer ligands: The use of phosphane and N-heterocyclic carbene ligands allows the Suzuki–Miyaura coupling of sterically encumbered aryl chlorides and bromides to aryl boronic acids with relatively low Pd loadings under mild conditions. Even the very bulky 2,4,6-triisopropylphenyl group can be employed in the coupling reaction in the presence of an appropriately designed phosphane ligand (for example, see formula).

A new bronze age: the described copper-mediated cross-coupling with double C-H activation can provide a convergent access to indole-containing biheteroaryls that are of high interest in pharmaceutical and medicinal chemistry. In this strategy an easily attachable and detachable 2-pyrimidyl directing group is used. Moreover, a variant that is catalytic in copper is achieved by using atmospheric oxygen as an ideal co-oxidant.

A matter of catalyst: Azole compounds can be directly alkylated with N-tosylhydrazones that bear unactivated alkyl groups (see scheme; phen=1,10-phenanthroline, Ts=p-toluenesulfonyl). Nickel catalysis enables the introduction of simple secondary alkyl chains into benzoxazole compounds, whereas the alkylation of 5-aryloxazoles and benzothiazole is possible by using a cobalt catalyst. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are p

Benzophosphole construction was achieved through the Ag(I) -mediated dehydrogenative annulation of phenylphosphine oxides with internal alkynes in a process involving CC and CP bond formation. A wide range of asymmetrical phenylacetylenes could be employed and the reactions proceeded with perfect regioselectivity. Moreover, the annulation could be conducted even at room temperature when a Mn(III) promoter was used in place of Ag(I) .

Some new types of copper-mediated intermolecular oxidative direct C-C (hetero)aromatic cross-couplings are described. A combination of the simple CuCl(2) salt and molecular oxygen allows 1,3-azoles to couple with terminal alkynes directly to form the corresponding heteroarylacetylenes. This direct version of Sonogashira-type coupling can be applied to the reaction with polyfluoroarenes. A copper acetate complex enables direct biaryl coupling between 2-arylazines and 1,3-azoles even in the absenc

Nitrogen (N) is ubiquitously found in bioactive molecules, pharmaceutical agents, and organic functional materials. Accordingly, development of new C-N bond-forming catalysis has been one of the long-standing research subjects in synthetic organic chemistry. In this Perspective, recent advances in highly selective amination reactions with electrophilic amination reagents are described: by taking advantage of the concept of nitrogen umpolung, otherwise challenging aminofunctionalizations, such as