250712-80-2Relevant academic research and scientific papers
Highly regioselective heck coupling reactions of aryl halides and dihydropyran in the presence of an NHC-pyridine ligand
Jarusiewicz, Jamiei,Kyung, Soo Yoo,Kyung, Woon Jung
body text, p. 482 - 486 (2009/08/09)
The Heck coupling reactions of aryl halides and 3,4-dihydro-2H-pyran facilitated the regioselective synthesis of arylated cyclic enol ethers. Good yields were obtained using 5 mol% of an NHC-ligand-Pd-catalyst complex in the presence of K2CO3 in DMF at 100°C. The use of this catalytic system broadens the substrate scope and improves the selectivity for this cross-coupling process. Georg Thieme Verlag Stuttgart.
The scope of the Heck arylation of enol ethers with arenediazonium salts: a new approach to the synthesis of flavonoids
Machado, Angelo H.L.,de Sousa, Marcio A.,Patto, Daniela C.S.,Azevedo, Luiz F.S.,Bombonato, Fernanda I.,Correia, Carlos Roque D.
supporting information; experimental part, p. 1222 - 1225 (2009/05/31)
The scope of the Heck arylation of cyclic and acyclic enol ethers with arenediazonium salts was evaluated. Arylation of 2,3-dihydrofuran yielded 2-aryl-2,5-dihydrofurans as the major adducts (>99:1) except when using n-Bu4NHSO4 as ad
A synthesis of densely functionalized 2,3-dihydropyrans using ring-closing metathesis and base-induced rearrangements of dihydropyran oxides
Schmidt, Bernd,Wildemann, Holger
, p. 3145 - 3163 (2007/10/03)
The preparation of dihydropyran and dihydrofuran oxides and their rearrangement in the presence of lithium dialkylamides to functionalized 2,3-dihydropyrans or 2,3-dihydrofurans, respectively, is described. The regiochemical outcome of the reaction can be influenced by the relative configuration of the starting epoxides and the steric demand of the base. The 2,3-dihydropyrans obtained were converted stereoselectively to difunctionalized 3,4-dihydropyrans by the carbon-Ferrier reaction, or to fused acetals by addition of dimedone, mediated by ceric ammonium nitrate. The stereochemical results are rationalized by mechanistic proposals.
Epoxide opening reactions of aryl substituted dihydropyran oxides: Regio- And stereochemical studies directed towards deoxy-aryl-Cglycosides
Schmidt, Bernd
, p. 2627 - 2637 (2007/10/03)
2-Aryl-substituted tetrahydropyrans with 3,4- or 4,5-/ra;w-configured oxo substituents have been synthesized via ring-closing metathesis of allyl homoallyl ethers, epoxidation of the resulting dihydropyrans and opening of the epoxides with O-nucleophiles
Base-induced rearrangement of dihydropyran oxides: A novel synthesis of cyclic enol ethers with a hydroxy-function in the allylic-position
Schmidt, Bernd
, p. 4319 - 4320 (2007/10/03)
A sequence of ring closing metathesis of allyl-homoallyl ethers, epoxidation of the resulting dihydropyrans, and rearrangements of the dihydropyran oxides with LDA provides convenient access to 2,3-dihydropyrans with a hydroxy group in the 4-position. The
