Benzofurans or Isochromenes via the Ring-Opening Cyclization of Cyclopropene Derivatives with Organolithiums
摘要:
A new and efficient approach to benzocycles from cyclopropene derivatives is described. Deprotection by organolithiums and subsequent ring-opening cyclization of the related 2-cyclopropenyl phenyl or benzyl acetates generated benzofurans and isochromenes in one pot.
Synthesis of 2-substituted 3-chlorobenzofurans <i>via</i> TMSCl-mediated nucleophilic annulation of isatin-derived propargylic alcohols
作者:Zhou Sun、Kuirong Xiang、Hua Tao、Liqun Guo、Ying Li
DOI:10.1039/c8ob01731j
日期:——
A TMSCl-mediated cascade annulation of isatin-derived propargylicalcohols for the synthesis of 2-substituted 3-chlorobenzofurans is now reported. Mechanistic investigations showed that this proceeded through a sequential Meyer–Schuster rearrangement/nucleophilic addition/intramolecular annulation. TMSCl not only acts as a promoter, but also acts as a chlorine source in this protocol.
Rhodium(III)-Catalyzed Cascade Cyclization/Electrophilic Amidation for the Synthesis of 3-Amidoindoles and 3-Amidofurans
作者:Zhiyong Hu、Xiaofeng Tong、Guixia Liu
DOI:10.1021/acs.orglett.6b00689
日期:2016.5.6
A rhodium(III)-catalyzed cascade cyclization/electrophilic amidation using N-pivaloyloxylamides as the electrophilic nitrogen source has been developed. This protocol provides an efficient route for the synthesis of 3-amidoindoles and 3-amidofurans under mild conditions with good functional group tolerance. The synthetic utility of this reaction has been demonstrated through the derivatization of the
Chemistry of aminophenols. Part 3: First synthesis of nitrobenzo[b]furans via a coupling–cyclization approach
作者:Wei-Min Dai、Kwong Wah Lai
DOI:10.1016/s0040-4039(02)02333-x
日期:2002.12
The first synthesis of 4-, 5-, and 6-nitrobenzo[b]furans has been achieved via the Sonogashira cross-coupling reaction of 2-iodonitrophenol acetates prepared from commercially available and inexpensive 2-aminonitrophenols. The obtained 2-alkynylnitrophenol acetates were subjected to a KOtBu-promoted cyclization at room temperature to form nitrobenzo[b]furans. Examples of the synthesis of other substituted
通过由市售和廉价的2-氨基硝基苯酚制备的2-碘硝基苯酚乙酸酯的Sonogashira交叉偶联反应已经实现了4-,5-和6-硝基苯并[ b ]呋喃的首次合成。将获得的2-炔基硝基苯酚乙酸酯在室温下进行KO t Bu促进的环化反应以形成硝基苯并[ b ]呋喃。给出了其他取代苯并[ b ]呋喃的合成和一锅偶联-环化的例子。
Novel Organic Synthesis through Ultrafast Chemistry
作者:Thomas Wirth
DOI:10.1002/anie.201609595
日期:2017.1.16
How fast are flashes? The field of flow chemistry has recently received increasing attention owing to the availability of commercial flow equipment. New syntheses with very short‐lived intermediates have been enabled by sub‐millisecond mixing and reaction regimes in tailor‐made flow devices.
Submillisecond organic synthesis: Outpacing Fries rearrangement through microfluidic rapid mixing
作者:Heejin Kim、Kyoung-Ik Min、Keita Inoue、Do Jin Im、Dong-Pyo Kim、Jun-ichi Yoshida
DOI:10.1126/science.aaf1389
日期:2016.5.6
carbon-carbon coupling before one of the reagents can undergo a Friesrearrangement that would shift a neighboring group to the coupling site. Science, this issue p. 691 Bimolecular coupling can outpace a fast unimolecular rearrangement via extremely rapid low-temperature microfluidic mixing. In chemical synthesis, rapid intramolecular rearrangements often foil attempts at site-selective bimolecular functionalization