Synthesis of Symmetrical Biaryls via Rhodium Catalyzed Dimerization of Arylmercurials and Mechanism of the Dimerization

A series of symmetrical biaryls was synthesized from arylmercuric chlorides and biarylmercurials in the presence of [ClRh(CO) 2] 2 in hexamethylphosphoramide(HMPA). The mechanism of the [ClRh(CO) 2] 2 catalyzed dimerization of biarylmercurials was studied, and shown to be mainly intermolecular reaction.

Merging C–H and C–C Activation in Pd(Ⅱ)-Catalyzed Enantioselective Synthesis of Axially Chiral Biaryls

The merging of C-H and C-C bond cleavage into one single chemical process remains a daunting challenge,especially in an asymmetric manner.Herein,a Pd(Ⅱ)-catalyzed enantioselective tandem C-H/C-C activation for the synthesis of axially chiral biaryls is described.Two types of simple cyclopropanes,such as vinylcyclopropanes and cyclopropanols,were used as efficient and readily available coupling partners.

Alkoxy substituted MeO-BIPHEP-type diphosphines ligands for asymmetric hydrogenation of aryl ketones

In this paper,a series of optically active MeO-BIPHEP-type ligands,(S)-6,6′-dimethoxy-2,2’-bis(di-p-alkoxyphenylphosphine)- 1,1′-biphenyl were synthesized and used to prepare the ruthenium complex.The effects of para-substituted were observed,the results showed that the ruthenium catalysts[diphosphine RuCl2 diamine]containing both t-Bu and i-Pr substitutions have better activities and enantioselectivities than the non-substituted ruthenium catalysts in the asymmetric hydrogenation of acetophenone.

Rhodium(III)-Catalyzed Atroposelective C-H Indolylization of 1-Aryl Isoquinolines with 3-Indolylphenyliodonium Salts

Rhodium(III)-catalyzed enantioselective C-H indolylization of isoquinolines was developed.The C-H coupling reactions between 1-aryl isoquinoline derivatives and 3-indolylphenyliodonium salts proceeded smoothly in the presence of a modified chiral cyclopentadienyl-Rh(III)complex,affording a series of axially chiral indolylated biaryl products in excellent yields and enantioselectivity(up to 98%yield and 95%ee).

Palladium-Catalyzed Denitrogenative Self-carbonylation of Arylhydrazine Using CO and O_(2) as an Ideal Oxidant

An efficient Pd/Cu-catalyzed oxidative self-carbonylation of arylhydrazine with CO and molecular oxygen as an oxidant to afford symmetrical biaryl ketones via C—N bond activation has been developed.In this approach,arylhydrazine hydrochlorides are used as a green arylating agent which releases nitrogen and water as byproducts.This developed protocol significantly restricts the formation of aryl iodide and homo-coupled azobenzene products even under favorable conditions.A library of symmetrical biaryl ketones with wide functionalities was synthesized in good yields under mild conditions.

Chiral Phosphoric Acid Catalyzed Asymmetric Synthesis of Axially Chiral Compounds

The well-defined conformational properties of axially chiral compounds bring extraordinary values to an assortment of bioactive molecules,advanced materials,organocatalysts as well as chiral ligands in asymmetric transformations.The demonstrated usefulness and untapped potential of axially chiral structural motifs stimulate increasing efforts to develop novel and efficient approaches for their preparation.In this regard,the chiral phosphoric acids broadly used in asymmetric Brønsted acid catalysis have shown high relevance for atroposelective synthesis as well.Our strong interest in reaction chemistry of atropisomers has established a rewarding research programme in our group.The course of studies will be recounted in this account,with discussion focused on the use of chiral phosphoric acids to catalyze construction of several key axially chiral structures such as BINAM,BINOL,NOBIN,arylquinones,SPINOL,arylpyrrole analogues and axially chiral alkenes.

Catalytic asymmetric Catellani-type reaction: A powerful tool for axial chirality construction

This highlight summarizes a recent development of a catalytic enantioselective Catellani-type reaction for the synthesis of axially chiral biaryls.The chirality induction is solely governed by chiral norbornene ligand in the Pd mediated ortho C–H functionalization and ipso cross-coupling transformation.The preparative power of the methodology is demonstrated as a powerful manifold for the divergent synthesis of structurally diverse axially chiral biaryls and chiral fluorenols.

Electrochemically time-dependent oxidative coupling/couplingcyclization reaction between heterocycles:tunable synthesis of polycyclic indole derivatives with fluorescence properties

A mild and practical protocol for selectively time-dependent dehydrogenative C–C coupling,as well as tandem couplingcyclization reaction between indoles or/and other heteroaromatics via electrochemically oxidative process has been demonstrated.The reaction runs under noble catalyst,external oxidant and inert gas free condition,allowing tunable access to a wide variety of synthetically useful symmetrical or nonsymmetrical heteroarene with aggregation-induced emission(AIE),and polycyclic 3-D indole derivatives with aggregation-caused quenching(ACQ)fluorescence properties.Finally,preliminary mechanistic study indicated that tunable generation of indole cation under various electrolysis potential via regulating Nprotecting group was the key to achieve cross-coupling between indoles and other heteroaromatics.

Pd(OAc)_(2)/PPh_(3)-Catalyzed Desulfonylative Homocoupling of Arylsulfonyl Chlorides

The Pd-catalyzed homodimerization with respect to arylsulfonyl chlorides as an efficient method for the synthesisof biaryls has been developed. This desulfonylative reaction which was performed at reflux in 1,4-dioxane for 4h under air afforded the desired products in good to excellent yields.

Catalytic Atroposelective Catellani Reaction Enables Construction of Axially Chiral Biaryl Monophosphine Oxides

An unprecedented atroposelective Catellani reaction between phosphine oxide-containing aryl bromides,aryliodides,and nucleophiles for the construction of phosphine-containing biaryl atropisomers was established using an enantiopure norbornene derivative as the chiral mediator.A broad range of atropisomeric biaryl-based monophosphine oxides were obtained in good efficiency with excellent enantioselectivity.

One-pot synthesis of salicylaldehyde containing biaryl frameworks via an aminocatalytic Diels-Alder-retro-Diels-Alder cascade reaction of ynals with 2-pyrones

Salicylaldehyde containing biaryls are efficiently synthesized via an unprecedented amine promoted Diels-Alderretro-Diels-Alder cascade reaction of ynals with 2-pyrones in good yields.The reaction is instrumentally metalfree,operationally simple and mild,and tolerates a diverse array of functional groups.

BrΦnsted acid-promoted ‘on-water’ C(sp^3)-H functionalization fot the synthesis of isoindolinone/[1,2,4]triazolo[1,5-a]pyrimidine derivatives targeting the SKP2-CKS1 interaction

The isoindolinone and biaryl scaffolds are prevalent in natural products and drug molecules,which have showed broad and interesting biological activities.The efficient construction of such hybridized molecules and biological evaluation are of great interest to medicinal chemistry community.In this communication,we report an efficient BrΦnsted acid-promoted C(sp^3)-H functionalization approach that enables the rapid construction of biologically important isoindolinone/[1,2,4]triazolo[1,5-a]pyrimidine hybrids from 5-methyl-7-(2,4,6-trimethoxyphenyl)-[1,2,4]triazolo[1,5-a]pyrimidine,2-formylbenzoic acid and various anilines.The title compounds were generated in high to excellent yields(up to 96%)regardless of the electronic nature and steric effects of the substituents.In this reaction,an isoindolinone scaffold,one C-C single bond,and two C-N bonds were formed simultaneously with high atom economy.In this work,we have envisioned that the methyl group linked to the electron-deficient Nheterocycles could be used as a new synthetic handle for late-state diversification and may have broad applications in the field of organic and medicinal chemistry.Besides,the title compounds have exhibited promising activity against the SKP2-CKS1 interaction.

Palladium-catalyzed ortho-C–H silylation of biaryl aldehydes using a transient directing group

A strategy for Pd-catalyzed ortho-C–H silylation of biaryl aldehydes enabled by a transient auxiliary is presented. This protocol provides a broad range of ortho-silylated biaryl aldehydes in good yields. The silyl moiety can be further functionalized under mild conditions, rendering the silylated products useful building blocks. Notably, this protocol also offers an opportunity to establish a platform for expeditious synthesis of structurally diverse axially chiral biaryl aldehydes via sequential atroposelective interannular C–H functionalization/intraanular C–H silylation.

Ion-Pairing Chirality Transfer in Atropisomeric Biaryl-Centered Gold Clusters

The stereocontrol of chiral metal clusters and nanoclusters has become a focus of interest in metal cluster chemistry due to their promising applications in asymmetric catalysis.Despite being a general chirality transfer strategy,the ion-pairing process is still ambiguous in the course of bestowing chirality to metal clusters.Here we construct a biaryl-centered axially chiral gold-cluster system to study an outside-in ion-pairing chirality transfer process.Four hexanuclear gold(I)clusters,centered by two types of biaryl ligands[(2-indolyl)aniline(L^(1))and biindole(L^(2))],were synthesized via in situ cyclization reactions.In the crystalline state,the biaryl centers showed axial chirality in which the gold atoms were in an asymmetric arrangement.In solution,the chiral phosphates induced an outside-in chirality transfer by significant interactions with the periphery of the biaryl-centered gold clusters.Finally,the chiral resolution of hexa-aurated biindoliums was accomplished via an efficient outside-in chirality transfer process relying on strong aurophilic interaction and extra peripheral coordination.This study not only deepens the understanding of the outside-in ion-pairing chirality transfer process but also provides a new approach for fabricating desired chiral metal clusters by a combination of organometallic transformation and chirality transfer.