1439-36-7Relevant articles and documents
Total synthesis of (+)-isomigrastatin
Krauss, Isaac J.,Mandal, Mihirbaran,Danishefsky, Samuel J.
, p. 5576 - 5579 (2007)
(Chemical Equation Presented) Marginally stable natural products: The asymmetric total synthesis of the hydrolytically and thermally labile natural product (+)-isomigrastatin was demonstrated. The thermodynamic instability of a 2E-configured double bond in the context of this 12-membered macrolide was further demonstrated by phosphine-catalyzed isomerization to the 2Z configuration.
The extremely low intrinsic reactivity of the P-(formylmethyl)triphenylphosphonium cation: An artefact due to strong covalent hydration of the carbonyl group
Moutiers,Peng,Peignieux,Pouet,Terrier
, p. 1287 - 1288 (1999)
The title cation is found to exhibit the lowest Marcus intrinsic reactivity known so far for a carbon acid; this situation is shown to reflect a rate-limiting hydration/ dehydration reaction of the aldehyde functionality.
Catalytic Synthesis of 1 H-2-Benzoxocins: Cobalt(III)-Carbene Radical Approach to 8-Membered Heterocyclic Enol Ethers
De Bruin, Bas,De Zwart, Felix J.,Li, Zirui,Mathew, Simon,Wolzak, Lukas A.,Zhou, Minghui
supporting information, p. 20501 - 20512 (2021/12/03)
The metallo-radical activation of ortho-allylcarbonyl-aryl N-arylsulfonylhydrazones with the paramagnetic cobalt(II) porphyrin catalyst [CoII(TPP)] (TPP = tetraphenylporphyrin) provides an efficient and powerful method for the synthesis of novel 8-membered heterocyclic enol ethers. The synthetic protocol is versatile and practical and enables the synthesis of a wide range of unique 1H-2-benzoxocins in high yields. The catalytic cyclization reactions proceed with excellent chemoselectivities, have a high functional group tolerance, and provide several opportunities for the synthesis of new bioactive compounds. The reactions are shown to proceed via cobalt(III)-carbene radical intermediates, which are involved in intramolecular hydrogen transfer (HAT) from the allylic position to the carbene radical, followed by a near-barrierless radical rebound step in the coordination sphere of cobalt. The proposed mechanism is supported by experimental observations, density functional theory (DFT) calculations, and spin trapping experiments.
Copper-Catalyzed N-O Cleavage of α,β-Unsaturated Ketoxime Acetates toward Structurally Diverse Pyridines
Ding, Xiaojuan,Duan, Jindian,Fang, Zheng,Guo, Kai,Li, Zhenjiang,Mao, Yiyang,Rong, Binsen,Xu, Gaochen,Zhang, Lei,Zhu, Ning
supporting information, p. 2532 - 2542 (2020/03/13)
The copper-catalyzed [4 + 2] annulation of α,β-unsaturated ketoxime acetates with 1,3-dicarbonyl compounds for the synthesis of three classes of structurally diverse pyridines has been developed. This method employs 1,3-dicarbonyl compounds as C2 synthons and enables the synthesis of multifunctionalized pyridines with diverse electron-withdrawing groups in moderate to good yields. The mechanistic investigation suggests that the reactions proceed through an ionic pathway.
Visible-light driven synthesis of polycyclic benzo[: D] [1,3]oxazocine from 2-aminochalcone
Chen, Junhan,Gao, Yu-Qi,He, Yu-Peng,Hou, Yi,Li, Ruoxin,Xie, Weiqing,Zhang, Sheng-Yong,Zhu, Liming
supporting information, p. 6739 - 6742 (2020/07/13)
Herein, we report a tandem cycloisomerization/nucleophilic addition/cyclization of 2-amino chalcone with bifunctional nucleophiles driven by visible light. This cascade process is realized by the irradiation of a blue LED at room temperature, which provides a concise route to structurally diverse benzo[d][1,3]oxazocine scaffolds. Mechanistic studies show that the reaction is initiated with the E to Z isomerization of a C-C double bond upon the irradiation of visible light, followed by cyclization/rearomatization to generate a transient quinolinium intermediate, which is trapped by the nucleophile and cyclized to produce the polycyclic benzo[d][1,3]oxazocine.
