Mechanistically Diverse Copper‐, Silver‐, and Gold‐Catalyzed Acyloxy and Phosphatyloxy Migrations: Efficient Synthesis of Heterocycles via Cascade Migration/Cycloisomerization Approach.

Abstract

Rearrangements O 0140Mechanistically Diverse Copper-, Silver-, and Gold-Catalyzed Acyloxy and Phosphatyloxy Migrations: Efficient Synthesis of Heterocycles via Cascade Migration/Cycloisomerization Approach. -The synthetic application of the phosphatyloxy-substituted heterocycles is demonstrated in the Kumada cross-coupling reaction with Grignard reagents. -(SCHWIER, T.; SROMEK, A. W.; YAP, D. M. L.; CHERNYAK, D.; GEVORGYAN*, V.; J. Am. Chem. Soc. 129 (2007) 32, p9868-p9878; Dep. Chem., Univ. Ill., Chicago, IL 60607, USA; Eng.) -Bartels 50-043

Homolytic C–O Cleavage in Phosphates and Sulfonates

“…studied Kumada coupling of heteroaromatic phosphates using a palladium-catalyzed system, and the high yields can be achieved in the coupling of phosphatyloxy-containing furan and indolizines with Grignard reagents. 13 Shi et al successfully performed the application of biaryl disulfates in Kumada coupling reaction, and all aryl groups can be transformed into the needed product with excellent efficiency. 14 Buchwald et al reported the Suzuki-Miyaura coupling of a series of aryl tosylates with boronic acids.…”

“…For instance, Chen et al successfully developed Suzuki-Miyaura cross-coupling of aryl phosphates with organoboron reagent using the best precatalyst of [NiCl 2 (Pcy 3 ) 2 ], which is inexpensive and bench-stable (Scheme ). Gevorgyan et al studied Kumada coupling of heteroaromatic phosphates using a palladium-catalyzed system, and the high yields can be achieved in the coupling of phosphatyloxy-containing furan and indolizines with Grignard reagents . Shi et al successfully performed the application of biaryl disulfates in Kumada coupling reaction, and all aryl groups can be transformed into the needed product with excellent efficiency .…”

Catalytic Conversion of Graphene into Carbon Nanotubes via Gold Nanoclusters at Low Temperatures

“…Historically, gold chemistry has received tremendous attention since Hatura’s discovery of oxide-supported Au nanocluster catalysts that were used for CO and H 2 oxidation at low temperatures. , Since then, the investigation of gold-based catalysts has increased drastically. ,,, Gold-based catalysts have been used in a range of organic transformations which includes a variety of nucleophilic addition, cascade reactions, C–C bond formation, Fridel-Crafts reaction, C–H bond activation, hydrogenation and dehydrogenation reactions, and oxidation chemistry. − Furthermore, asymmetric catalysis and total organic synthesis have also been achieved using Au-based catalysts . Highly flexible catalytic systems consisting of carbon supports decorated with AuNPs, have shown significant potential for many reactions including the oxidation of CO for fuel cells, oxidation of diols, and C–C bond formation. ,, Therefore, synthesizing carbon nanomaterials on an Au catalyst or decorating graphitic nanostructures with AuNPs opens the door to a wide range of new applications for which current technologies are not adequate.…”

Synthesis of -Tosyloxylated gem-Difluoroalkanes via Oxidative Fluorination of Vinyl Sulfonates Featuring A [2,3]-Sulfonyloxy Migration

“…In another vein, the hydrolysis of β-difluoroalkyl sulfonate 2u furnished a β-difluoroalkyl alcohol 15 in good yield, which can be further oxidized 20 to a-difluorocarboxylic acid 16 or converted to β-difluoroalkyl sulfonic acid 17 21 , a potential surfactant 22 , efficiently. On the basis of literature precedents, 11,23 a plausible mechanism for this [2,3]-sulfonyloxy migration was proposed and briefly depicted in Scheme 5. Initially, the coordination of vinyl sulfonate with aryl difluoroiodine (A) triggers a regioselective vicinal fluoroiodination to produce intermediate B.…”