Palladium(II)‐Catalyzed Synthesis of Isoxazolidines: Using a Catalytic Copper Acetate and Molecular Oxygen as the Cooxidant
摘要:
An environmentally friendly process is reported for the palladium(II)-catalyzed cyclofunctionalization of allylic hydroxylamine derivatives using a catalytic amount of copper(II) acetate and molecular oxygen as the cooxidant.
Stereoselective Isoxazolidine Synthesis Via Copper-Catalyzed Alkene Aminooxygenation
作者:Shuklendu D. Karyakarte、Thomas P. Smith、Sherry R. Chemler
DOI:10.1021/jo3013226
日期:2012.9.7
Isoxazolidines are useful in organic synthesis, drug discovery, and chemical biology endeavors. A new stereoselective synthesis of methyleneoxy-substituted isoxazolidines is disclosed. The method involves copper-catalyzed aminooxygenation/cyclization of N-sulfonyl-O-butenyl hydroxylamines in the presence of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl radical (TEMPO) and O2 and provides substituted isoxazolidines
Stereoselective Electrophilic
Cyclisation of <i>O</i>-Homoallyl Hydroxylamine Derivatives
作者:Armido Studer、Birgit Janza
DOI:10.1055/s-2002-34385
日期:——
isoxazolidines with moderate cis-selectivity (up to 7: 1). Electrophilic cyclisation of N-acylated O-homoallyl hydroxylamines provides isoxazolines or isoxazolidines depending on the reaction conditions (reagents). The t-BuOCl-mediated cyclisation affords isoxazolines via an oxidative cyclisation, whereas the NIS-induced reaction provides the 5-exo-cyclisation product with high stereoselectivity (cis:trans =
Influence of Hydroxylamine Conformation on Stereocontrol in Pd-Catalyzed Isoxazolidine-Forming Reactions
作者:Georgia S. Lemen、Natalie C. Giampietro、Michael B. Hay、John P. Wolfe
DOI:10.1021/jo8027399
日期:2009.3.20
Palladium-catalyzed carboamination reactions between N-Boc-O-(but-3-enyl)hydroxylamine derivatives and aryl or alkenyl bromides afford cis-3,5- and trans-4,5-disubstituted isoxazolidines in good yield with up to >20:1 dr. The diastercoselectivity observed in the formation of cis-3,5-disubstituted isoxazolidines is superior to selectivities typically obtained in other transformations, such as 1,3-dipolar cycloaddition reactions, that provide these products. In addition, the stereocontrol in the C-N bond-forming Pd-catalyzed carboamination reactions of N-Boc-O-(but-3-enyl)hydroxylamines is significantly higher than that of related C-O bond-forming carboetherification reactions of N-benzyl-N-(but-3-enyl)hydroxylamine derivatives. This is likely due to a stereoelectronic preference for cyclization via transition states in which the Boc group is placed in a perpendicular orientation relative to the plane of the developing ring, which derives from the conformational equilibria of substituted hydroxylamines.
Palladium(0)-catalyzed cascade one-pot synthesis of isoxazolidines
作者:Krishna Gopal Dongol、Boon Ying Tay
DOI:10.1016/j.tetlet.2005.11.148
日期:2006.2
A highly diastereoselective cascade reaction protocol has been developed for the synthesis of isoxazolidine derivatives utilizing aryl halides, O-homoallyl hydroxylamine and palladium(0) in a one-pot reaction. (c) 2005 Elsevier Ltd. All rights reserved.
Palladium/norbornene-catalyzed distal alkenyl C–H arylation and alkylation of cis-olefins
作者:Zhao Wu、Nina Fatuzzo、Guangbin Dong
DOI:10.1016/j.tet.2021.132173
日期:2021.6
In this full article, a detailed study of a distal alkenyl C–H arylation and alkylation through the palladium/norbornene (NBE) cooperative catalysis is described. Both aminopyridine- and oxime ether-type directing groups have been found effective for this transformation, allowing functionalization of diverse allyl amines and homoallyl alcohols. In addition, the C5,C6-substititued NBEs show optimal