106824-47-9Relevant academic research and scientific papers
The reaction of o-alkynylarene and heteroarene carboxaldehyde derivatives with iodonium ions and nucleophiles: A versatile and regioselective synthesis of 1H-isochromene, naphthalene, indole, benzofuran, and benzothiophene compounds
Barluenga, Jose,Vazquez-Villa, Henar,Merino, Isabel,Ballesteros, Alfredo,Gonzalez, Jose M.
, p. 5790 - 5805 (2006)
The reaction of o-alkynyl-benzaldehydes 1 with different alcohols, silylated nucleophiles 5, electronrich arenes 10, and heteroarenes 12 in the presence of the reagent IPy2BF4, at room temperature, gave functionalized 4-iodo-1H-isochromenes 2, 6, 11, and 13 in a regioselective manner. When alkynes 16 and alkenes 19 and 20 were used as nucleophiles, a regioselective benzannulation reaction took place to form 1-iodonaphthalenes 17 and 1-naphthyl ketones 18, respectively. Moreover, the latter process has been adapted to accomplish the synthesis of indole, benzofuran, and benzothiophene derivatives (23, 27, and 28, respectively). The three patterns of reactivity observed for the o-alkynylbenzaldehyde derivatives with IPy2BF 4 stem from a common iodinated isobenzopyrylium ion intermediate, A, that evolves in a different way depending on the nucleophile present in the reac-tion medium. A mechanism is proposed and the different reaction pathways observed as a function of the type of nucleophile are discussed. Furthermore, the reaction of the o-hexynyl-benzaldehyde 1b with styrene was monitored by NMR spectroscopy. Compound III, a resting state for the common intermediate in the absence of acid, has been isolated. Its evolution in acid media has been also tested, thereby providing support to the proposed mechanism.
Bioinspired Total Synthesis of (±)-Chaetophenol C Enabled by a Pd-Catalyzed Cascade Cyclization
Li, Yun,Zhang, Qingyu,Wang, Hongyu,Cheng, Bin,Zhai, Hongbin
supporting information, p. 4387 - 4390 (2017/08/23)
A novel Pd(II)-catalyzed cascade reaction has been developed that consists of a highly regio- and stereoselective oxa [4 + 2] cycloaddition reaction of o-alkynylbenzaldehydes and an intramolecular carboxylic group quenching of the in situ generated oxonium ion. This new reaction provides a one-step construction of the tetracyclic core structure of chaetophenol C from two simple starting materials. The developed chemistry was successfully applied to the first total synthesis of chaetophenol C and dozens of its analogues.
Catalytic Asymmetric 1,3-Dipolar Cycloaddition/Hydroamination Sequence: Expeditious Access to Enantioenriched Pyrroloisoquinoline Derivatives
Molina, Alba,Pascual-Escudero, Ana,Adrio, Javier,Carretero, Juan C.
, p. 11238 - 11246 (2017/10/27)
A three-step reaction sequence has been developed to prepare a variety of enantioenriched pyrroloisoquinoline derivatives. The process involves a catalytic asymmetric azomethine ylide 1,3-dipolar cycloaddition followed by an intramolecular AuI-catalyzed alkyne hydroamination and enamine reduction.
CONDENSED HETEROAROMATIC RING SYSTEMS. XI. A FACILE SYNTHESIS OF ISOQUINOLINE N-OXIDES
Sakamoto, Takao,Kondo, Yoshinori,Miura, Norio,Hayashi, Kazuhiko,Yamanaka, Hiroshi
, p. 2311 - 2314 (2007/10/02)
Isoquinoline 2-oxides (5a-f) were obtained by the cyclization of 2-ethynylbenzaldehyde oxime (4a-f) under basic conditions.The starting compounds (4a-f) were easily synthesized by the palladium-catalyzed reaction of 2-bromobenzaldehydes (1 and 2) with terminal acetylenes, and subsequent oximation of the resulting 2-ethynylbenzaldehydes (3a-f).
