Effective Transmetalation from Gold to Iron or Ruthenium

The transmetalation of aryl, alkynyl, and alkyl groups from organogold compounds to iron complexes offers an efficient synthesis of organoiron complexes under very mild conditions. This method could be extended to ruthenium complexes

Effective Transmetalation from Gold to Iron or Ruthenium

The transmetalation of aryl, alkynyl, and alkyl groups from organogold compounds to iron complexes offers an efficient synthesis of organoiron complexes under very mild conditions. This method could be extended to ruthenium complexes

Silver-Catalyzed Decarboxylative Alkynylation of α,α-Difluoroarylacetic Acids with Ethynylbenziodoxolone Reagents

A decarboxylating alkynylation of α,α-difluoroarylacetic acids with ethynylbenziodoxolone reagents is reported. AgNO₃ serves as the catalyst and K₂S₂O₈ as the oxidant. A series of functional groups were tolerated, and moderate to good yields were obtained

Saturated Abnormal NHC–Gold(I) Complexes: Synthesis and Catalytic Activity

New saturated abnormal N-heterocyclic carbene complexes of gold­(I) have been prepared by a 1,3-dipolar cycloaddition of an in situ generated azomethine ylide with an isocyanogold­(I) choride. A series of different substituents on the nitrogen atom of the 1,3-dipole are tolerated without problem. Substitutents on a carbon atom of the 1,3-dipole are problematic in the case of the isocyanogold­(I) chlorides; only low yields are obtained. However, the corresponding isocyanogold­(I) iodide shows good reactivity, and these abnormal N-heterocyclic carbenes bear the substituent in a position α to the carbene carbon, as proven by a crystal structure analysis of one of the products. Some of the new saturated abnormal N-heterocyclic carbene complexes were then tested in the gold-catalyzed phenol synthesis; moderate turnover numbers of 252–380 could be reached

Efficient One-Pot Synthesis of Unsymmetrical Gold(I) N-Heterocyclic Carbene Complexes and Their Use as Catalysts

Eleven different gold­(I) complexes of new NHC ligands were prepared in excellent yield, demonstrating the versatility of the new route to NHC complexes. While the influence of electronically different ligands on the synthesis of the catalysts was small, the catalytic activities of the products differed significantly

Diastereoselective Formation of a New Palladacycle and Organic Compounds Derived from Vinylcarbenoids as Side Products in the Synthesis of 5-Pallada-<i>trans</i>-tricyclo[4.1.0.0^2,4]heptanes from Acceptor-Substituted Cyclopropenes

When a large excess of dimethyl 3,3-dimethylcyclopropene-1,2-dicarboxylate was used in a reaction with Pd2(dba)3·CHCl3, only reduced yields of tetramethyl 3,3,7,7-tetramethyl-5-pallada-trans-tricyclo[4.1.0.02,4]heptane-1,2,4,6-tetracarboxylate were obtained. One side product was the new palladacyle dimethyl 3-(3,4-bis(methoxycarbonyl)-5,5-dimethyl-5H-furan-2-ylidene)-1,1,4,4-tetramethyl-6-oxodihydro-5-oxa-2-palladacyclopropa[c]pentalene 1a,3a-dicarboxylate; its structure was proven by a crystal structure analysis of the bpy complex. The other side products are the 1,3,5-triene methyl (Z)-2-isopropylidene-3,4,5-tris(methoxycarbonyl)-6-methylhepta-3,5-dienecarboxylate (14), the allyl alcohol dimethyl (Z)-2-(1-hydroxy-1-methylethyl)but-2-enedicarboxylate (15), the 1,3-diene dimethyl (Z)-2-isopropenylbut-2-enedicarboxylate (16), and the allyl ether dimethyl 2-isopropylidene-3-methoxysuccinate (17). The formation of most of these side products is interpreted as the reaction of a vinyl carbenoid species with O-nucleophiles

Asymmetric Synthesis of Palladacycles by Regioselective Oxidative Cyclization of <i>C</i>₂-Symmetrical, Chiral Alkenes and Determination of the Configuration of All Stereocenters

The reaction of Pd2(dba)3·CHCl3 with 2 equiv of chiral, C2-symmetrical cyclopropenes bearing lactate esters at the 1- and 2-positions provided trans-5-palladatricyclo[4.1.0.02,4]heptanes (PTHs) in high diastereomeric excess. The configuration of all stereocenters in the major diastereomer was determined by X-ray structure analyses of the complexes of the PTH with norbornadiene; the C2 symmetry of the (+)-DIOP complex of the minor diastereomer proves that this was also a trans isomer

Benzaldehyde- and Nickel-Catalyzed Photoredox C(sp³)–H Alkylation/Arylation with Amides and Thioethers

Herein a synergistic combination of a nickel catalyst and benzaldehyde for the utilization of amides and thioethers in C­(sp3)–H alkylation and arylation reactions employing simple aryl or alkyl halides is reported. This method provides a simple and cheap strategy for the direct functionalization of amides and thioethers. Readily available starting materials, mild reaction conditions, a good functional-group tolerance, and a broad substrate scope make this methodology attractive and practical for pharmaceutical and synthetic chemistry

Saturated Abnormal NHC–Gold(I) Complexes: Synthesis and Catalytic Activity

New saturated abnormal N-heterocyclic carbene complexes of gold­(I) have been prepared by a 1,3-dipolar cycloaddition of an in situ generated azomethine ylide with an isocyanogold­(I) choride. A series of different substituents on the nitrogen atom of the 1,3-dipole are tolerated without problem. Substitutents on a carbon atom of the 1,3-dipole are problematic in the case of the isocyanogold­(I) chlorides; only low yields are obtained. However, the corresponding isocyanogold­(I) iodide shows good reactivity, and these abnormal N-heterocyclic carbenes bear the substituent in a position α to the carbene carbon, as proven by a crystal structure analysis of one of the products. Some of the new saturated abnormal N-heterocyclic carbene complexes were then tested in the gold-catalyzed phenol synthesis; moderate turnover numbers of 252–380 could be reached

Highly Selective Gold-Catalyzed Arene Synthesis

Highly Selective Gold-Catalyzed Arene Synthesi