1016926-23-0Relevant articles and documents
Oxidation of 3-furfurylcarbinols with bromine in acetone-water
Harn, Piin-Jye,Lin, Chu-Chung,Wu, Hsien-Jen
, p. 233 - 238 (2008)
Oxidation of 3-furfurylcarbinols 3a-e and 7 with bromine in acetone-water solution gave the 2-substituted-3-furfurals 4a-e and 8 in good yields, respectively. Reaction of 2-alkyl-3-furfurylcarbinols 9a and 9b with bromine in acetone-water gave the bromoal
Ruthenium(0)-Catalyzed C-H Arylation of Aromatic Imines under Neutral Conditions: Access to Biaryl Aldehydes
Hu, Feng,Szostak, Michal
, p. 4186 - 4189 (2016/09/09)
The first ruthenium(0)-catalyzed C-H bond arylation of aromatic imines with arylboronates under neutral conditions is reported. This versatile method provides rapid access to a wide range of biaryl aldehydes that are difficult to assemble using traditional methods with high atom economy. A new hydrogen acceptor for Ru(0) arylation has been identified. This atom-economical strategy has potential for an array of direct applications in Ru(0)-catalyzed C-H bond arylations using removable directing groups. An indole synthesis by a sequential one-pot, multiple C-H activation protocol is reported.
Singlet-oxygen-induced rearrangement of furan derivatives
Charbonnet, Nicolas,Riguet, Emmanuel,Bochet, Christian G.
supporting information; experimental part, p. 2231 - 2233 (2011/11/06)
Upon exposure to singlet oxygen and dimethylsulfide, the addition products between 3-furaldehydes and Grignard reagents undergo an oxidative rearrangement to give 2-substituted 3-furaldehydes, in yields ranging from 26-83%. N-Aryl- and N-tosylpyrroles were similarly obtained if the corresponding nitrogen-containing precursors were used instead, in equally attractive yields (64-92%). Georg Thieme Verlag Stuttgart - New York.
Addition/oxidative rearrangement of 3-furfurals and 3-furyl imines: New approaches to substituted furans and pyrroles
Kelly, Ann Rowley,Kerrigan, Michael H.,Walsh, Patrick J.
, p. 4097 - 4104 (2008/09/21)
Furans and pyrroles are important synthons in chemical synthesis and are commonly found in natural products, pharmaceutical agents, and materials. Introduced herein are three methods to prepare 2-substituted 3-furfurals starting from 3-furfural, 3-bromofuran, and 3-vinylfurans. Addition of a variety of organofithium, Grignard, and organozinc reagents (M-R) to 3-furfural provides 3-furyl alcohols in high yields. Treatment of these intermediates with NBS initiates a novel oxidative rearrangement that results in the installation of the R group in the 2 position of the 2-substituted 3-furfurals. Likewise, metalation of 3-bromofuran with n-BuLi and addition to benzaldehyde provides a furyl alcohol that is converted to 2-phenyl 3-furfural upon oxidative rearrangement. Enantioenriched disubstituted furans can be prepared starting with the Sharpless asymmetric dihydroxylation of 3-vinylfurans. The resulting enantioenriched diols undergo the oxidative rearrangement to furnish enantioenriched 2-substituted 3-furfurals with excellent transfer of asymmetry. This later method has been applied to the enantioselective preparation of an intermediate in Honda's synthesis of the natural product (-)-canadensolide. Mechanistic studies involving deuterium-labeled furyl alcohol suggest that the oxidative rearrangement proceeds through an unsaturated 1,4-dialdehyde intermediate. The alcohol then cyclizes onto an aldehyde, resulting in the elimination of water and rearomatization. On the basis of this proposed mechanism, we found that 3-furyl imines undergo the addition of organometallic reagents to provide furyl sulfonamides. Under the oxidative rearrangement conditions, 2-substituted 3-formyl pyrroles are formed, providing a novel route to these heterocycles. In contrast to the metalation of heterocycles, which often lead to mixtures of regioisomeric products, these new oxidative rearrangements of furyl alcohols and furyl sulfonamides generate only one regioisomer in each case.
