Dirhodium Carboxylates Research Articles

Catalytic enantioselective C–H functionalization of indoles with α-diazopropionates using chiral dirhodium(II) carboxylates: asymmetric synthesis of the (+)-α-methyl-3-indolylacetic acid fragment of acremoauxin A

An enantioselective C–H functionalization of N-methoxymethyl (MOM)-protected 2,3-unsubstituted indoles with α-diazopropionates has been effected via catalysis by dirhodium(II) tetrakis[ N-phthaloyl-( S)-triethylalaninate], Rh 2(( S)-PTTEA) 4, providing α-methyl-3-indolylacetates in high yields and with enantioselectivities of up to 86% ee. The effectiveness of this protocol was demonstrated by the first catalytic asymmetric synthesis of the (+)-α-methyl-3-indolylacetic acid fragment of acremoauxin A, a potent plant-growth inhibitor. Furthermore, the Fujioka protocol using a combination of TMSOTf and 2,2′-bipyridyl was shown to be superior for the removal of the N-MOM group.

ロジウム(II)カルボキシラート錯体を用いた触媒的不斉アミノ化反応

ロジウム(II)カルボキシラート錯体を用いた触媒的不斉アミノ化反応

ChemInform Abstract: Asymmetric Intermolecular N—H Insertion Reaction of Phenyldiazoacetates with Anilines Catalyzed by Achiral Dirhodium(II) Carboxylates and Cinchona Alkaloids.

AbstractA novel catalytic system consisting of a rhodium salt and dihydrocinchonine is used for the synthesis of phenylglycine derivatives (III) by asymmetric N‐H insertion reaction of phenyldiazoacetate (I) with anilines (II).

Asymmetric Intermolecular N-H Insertion Reaction of Phenyldiazoacetates with Anilines Catalyzed by Achiral Dirhodium(II) Carboxylates and Cinchona Alkaloids

Asymmetric Intermolecular N-H Insertion Reaction of Phenyldiazoacetates with Anilines Catalyzed by Achiral Dirhodium(II) Carboxylates and Cinchona Alkaloids

ChemInform Abstract: Enantioselective Construction of a 2,8‐Dioxabicyclo[3.2.1]octane Ring System via [2,3]‐Sigmatropic Rearrangement of Oxonium Ylide Using Chiral Dirhodium(II) Carboxylates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Asymmetric Synthesis of Neolignans (−)-epi-Conocarpan and (+)-Conocarpan via Rh(II)-Catalyzed C−H Insertion Process and Revision of the Absolute Configuration of (−)-epi-Conocarpan

Catalytic asymmetric synthesis of neolignan natural products (-)-epi-conocarpan and (+)-conocarpan has been achieved by exploiting an enantio- and diastereoselective intramolecular C-H insertion reaction to construct a cis-2-aryl-2,3-dihydrobenzofuran ring system as a key step. The C-H insertion reaction of 5-bromoaryldiazoacetate catalyzed by Rh(2)(S-PTTEA)(4), a new dirhodium(II) carboxylate complex that incorporates N-phthaloyl-(S)-triethylalaninate as chiral bridging ligands, provided 2-aryl-5-bromo-3-methoxycarbonyl-2,3-dihydrobenzofuran with exceptionally high diastereoselectivity (cis/trans = 97:3) and high enantioselectivity for the cis isomer (84% ee).

Enantioselective Construction of a 2,8-Dioxabicyclo[3.2.1]octane Ring System via [2,3]-Sigmatropic Rearrangement of Oxonium Ylide Using Chiral Dirhodium(II) Carboxylates

Abstract Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh2(S-TFPTTL)4, is an exceptionally efficient catalyst for enantioselective tandem cyclic oxonium ylide formation and [2,3]-sigmatropic rearrangement from α-diazo-β-ketoester bearing cyclic allylic acetal functionality, providing the 2,8-dioxabicyclo[3.2.1]octane core structure of zaragozic acids in up to 93% ee.

Asymmetric approach to the pentacyclic skeleton of Aspidosperma alkaloids via enantioselective intramolecular 1,3-dipolar cycloaddition of carbonyl ylides catalyzed by chiral dirhodium(II) carboxylates

This Letter describes asymmetric tandem carbonyl ylide formation–intramolecular 1,3-dipolar cycloaddition reaction of diazo imides containing a tethered indole catalyzed by chiral dirhodium(II) carboxylates as an approach to the pentacyclic skeleton of Aspidosperma alkaloids. The cycloaddition of carbonyl ylides derived from indolyl-substituted 2-diazo-5-imido-3-ketoesters under the influence of dirhodium(II) tetrakis[ N-tetrachlorophthaloyl-( S)- tert-leucinate], Rh 2( S-TCPTTL) 4, provides cycloadducts in moderate yields and enantioselectivities of up to 66% ee as well as with perfect endo diastereoselectivity. This is the first example of asymmetric induction in an intramolecular cycloaddition of a carbonyl ylide across an indolyl π-bond.

Complexes of dirhodium(II) carboxylates with calix[4]resorcinarenes functionalized at the upper and lower rim of the molecule with P,N-containing Fragments

The features of the reaction between dirhodium(II) carboxylate and calix[4]resorcinarenes modified with various type functional groups at the upper and lower rim of the molecule in protic anhydrous solvent (ethanol) under inert atmosphere were investigated. Neutral complex compounds were isolated formed as a result of substitution of a water molecule by the macroligand in the axial position with respect to the R\( \tilde h \)Rh bond occurring with the conservation of the latter. The compounds were characterized by 31P NMR, UV, IR, Raman, and ESR spectroscopy. Their composition was confirmed by elemental analysis.

ChemInform Abstract: Catalytic Enantioselective Intermolecular Cycloaddition of 2‐Diazo‐3,6‐diketoester‐Derived Carbonyl Ylides with Alkynes and Styrenes Using Chiral Dirhodium(II) Carboxylates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Catalytic Enantioselective Intermolecular Cycloaddition of 2-Diazo-3,6-diketoester-Derived Carbonyl Ylides with Alkynes and Styrenes Using Chiral Dirhodium(II) Carboxylates

Dirhodium(II) tetrakis[ N-tetrachlorophthaloyl-( S)- tert-leucinate], Rh 2( S-TCPTTL) 4, is an exceptionally effective catalyst for enantioselective tandem carbonyl ylide formation-cycloaddition reactions of 2-diazo-3,6-diketoesters with arylacetylene, alkoxyacetylene, and styrene dipolarophiles, providing cycloadducts in good to high yields and with enantioselectivities of up to 99% ee as well as with perfect exo diastereoselectivity for styrenes.

ChemInform Abstract: Enantioselective Amination of Silylketene Acetals with (N‐Arylsulfonylimino)phenyliodinanes Catalyzed by Chiral Dirhodium(II) Carboxylates: Asymmetric Synthesis of Phenylglycine Derivatives.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Catalytic Enantioselective Amination of Silyl Enol Ethers Using Chiral Dirhodium(II) Carboxylates: Asymmetric Formal Synthesis of (‐)‐Metazocine.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ロジウム(II)カルボキシラート錯体触媒を用いるカルボニルイリドの分子間付加環化反応

ロジウム(II)カルボキシラート錯体触媒を用いるカルボニルイリドの分子間付加環化反応

Enantioselective amination of silylketene acetals with ( N-arylsulfonylimino)phenyliodinanes catalyzed by chiral dirhodium(II) carboxylates: asymmetric synthesis of phenylglycine derivatives

The first catalytic enantioselective amination of silylketene acetals with ( N-arylsulfonylimino)phenyliodinanes is described. The reaction of silylketene acetals derived from methyl phenylacetates with [ N-(2-nitrophenylsulfonyl)imino]phenyliodinane (NsN = IPh) under the catalysis of dirhodium(II) tetrakis[ N-tetrachlorophthaloyl-( S)- tert-leucinate], Rh 2( S-TCPTTL) 4, proceeds in benzene at room temperature to give N-(2-nitrophenylsulfonyl)phenylglycine derivatives in high yields and with enantioselectivities of up to 99% ee.

Catalytic Enantioselective Amination of Silyl Enol Ethers Using Chiral Dirhodium(II) Carboxylates: Asymmetric Formal Synthesis of (−)-Metazocine

Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh2(S-TFPTTL)4, is an exceptionally efficient catalyst for enantioselective aminations of silyl enol ethers derived from acyclic ketones or alpha,beta-enones with [N-(2-nitrophenylsulfonyl)imino]phenyliodinane (NsN=IPh), providing N-(2-nitrophenylsulfonyl)-alpha-amino ketones in high yields and with enantioselectivities of up to 95% ee. The effectiveness of the present catalytic protocol has been demonstrated by an asymmetric formal synthesis of (-)-metazocine.

Catalytic Enantioselective Aziridination of Alkenes Using Chiral Dirhodium(II) Carboxylates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Enantioselective Synthesis of 3‐Arylindan‐1‐ones via Intramolecular C—H Insertion Reactions of α‐Diazo‐β‐ketoesters Catalyzed by Chiral Dirhodium(II) Carboxylates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Enantioselective Intramolecular C—H Amidation of Sulfamate Esters Catalyzed by Chiral Dirhodium(II) Carboxylates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Characterization of adducts formed between Dirhodium(II,II) carboxylates and DNA

Characterization of adducts formed between Dirhodium(II,II) carboxylates and DNA