Palladium(II)-catalyzed coupling of allenoic acids and α,β-unsaturated carbonyl compounds through tandem intramolecular oxypalladation and conjugate addition reactions
作者:Guosheng Liu、Xiyan Lu
DOI:10.1016/s0040-4039(02)02507-8
日期:2003.1
A regioselective divalent palladium-catalyzed tandem coupling reaction of allenoic acids with α,β-unsaturated carbonylcompounds was developed. The reaction involves intramolecular oxypalladation of an allene, followed by insertion of the α,β-unsaturated carbonylcompound and protonolysis of the CPd bond to regenerate the Pd(II) species in the presence of excess halide ions. Functionalized lactones
Heteroatom-Nucleophile-Induced CC Fragmentations: Synthesis of Allenes and Entry to Domino Reactions
作者:Tanguy Saget、Nicolai Cramer
DOI:10.1002/anie.201004795
日期:2010.11.15
Blessed are the piece‐makers: Heteroatom nucleophiles (NuH) induce Grob‐type fragmentations of vinyl triflates under mild conditions and provide ω‐allene‐functionalized carboxylic acid derivatives. These products are a versatile starting point for domino and one‐pot reactions accessing a range of structurally diverse scaffolds in good yields.
Asymmetric Gold-Catalyzed Lactonizations in Water at Room Temperature
作者:Sachin Handa、Daniel J. Lippincott、Donald H. Aue、Bruce H. Lipshutz
DOI:10.1002/anie.201404729
日期:2014.9.26
Asymmetric gold‐catalyzed hydrocarboxylations are reported that show broad substrate scope. The hydrophobic effect associated with in situ‐formed aqueous nanomicelles gives good to excellent ee’s of product lactones. In‐flask product isolation, along with the recycling of the catalyst and the reaction medium, are combined to arrive at an especially environmentally friendly process.
Silica-Supported Cationic Gold(I) Complexes as Heterogeneous Catalysts for Regio- and Enantioselective Lactonization Reactions
作者:Xing-Zhong Shu、Son C. Nguyen、Ying He、Fadekemi Oba、Qiao Zhang、Christian Canlas、Gabor A. Somorjai、A. Paul Alivisatos、F. Dean Toste
DOI:10.1021/jacs.5b04294
日期:2015.6.10
catalysts has been developed. These catalysts were easily assembled from readily available silica materials and gold complexes. The heterogeneous catalysts exhibited superior reactivity in various reactions where protodeauration is the rate-limiting step. Dramatic enhancement in regio- and enantioselectivity was observed when compared to the homogeneous unsupported gold catalyst. The catalysts are easily
Allene epoxidation: synthesis of functionalized lactones by the DMDO oxidation of allenic acids
作者:Jack K Crandall、Elisa Rambo
DOI:10.1016/s0040-4020(02)00698-1
日期:2002.8
products are formed directly from allene oxides, keto lactones are formed. The corresponding spirodioxide intermediates give lactones with appropriately situated α-hydroxyketone moieties. An understanding of the regiochemistry of the epoxidations and the subsequent cyclizations of the reactiveintermediates is developed, as are methods for the manipulation of the experimental conditions to favor the