Copper-Catalyzed Enantioselective Hydroalkoxylation of Alkenols for the Synthesis of Cyclic Ethers
作者:Dake Chen、Ilyas A. Berhane、Sherry R. Chemler
DOI:10.1021/acs.orglett.0c01691
日期:2020.10.2
The copper-catalyzedenantioselective intramolecular hydroalkoxylation of unactivated alkenes for the synthesis of tetrahydrofurans, phthalans, isochromans, and morpholines from 4- and 5-alkenols is reported. The substrate scope is complementary to existing enantioselective alkene hydroalkoxylations and is broad with respect to substrate backbone and alkene substitution. The asymmetric induction and
general, and functional group tolerant intramolecular hydroalkoxylation and hydroacyloxylation of unactivated olefins using a Co(salen) complex, an N-fluoropyridinium salt, and a disiloxane reagent is described. This reaction was carried out at room temperature and afforded five- and six-membered oxygen heterocyclic compounds, such as cyclic ethers and lactones. The Co complex was optimized for previously
描述了使用 Co(salen) 配合物、N-氟吡啶鎓盐和二硅氧烷试剂对未活化烯烃进行温和、通用和官能团耐受的分子内加氢烷氧基化和加氢酰氧基化。该反应在室温下进行,得到五元和六元氧杂环化合物,如环醚和内酯。通过未活化烯烃的加氢官能化,Co 配合物针对先前稀有介质环的形成进行了优化。强大的 Co 催化剂体系还可以使 O-保护的链烯醇脱保护加氢烷氧基化和链烯基酯加氢酰氧基化,直接得到环醚和内酯。研究了脱保护的底物范围和机理证明。
Copper-Catalyzed Intramolecular Alkene Carboetherification: Synthesis of Fused-Ring and Bridged-Ring Tetrahydrofurans
作者:Yan Miller、Lei Miao、Azade S. Hosseini、Sherry R. Chemler
DOI:10.1021/ja3034075
日期:2012.7.25
to 75% ee) and provide evidence that copper is involved in the alkene addition step, likely through a cis-oxycupration mechanism. Catalytic enantioselective alkene carboetherification reactions are rare and future development of this new method into a highlyenantioselective process is promising. During the course of the mechanistic studies a protocol for alkene hydroetherification was also developed
稠环和桥环四氢呋喃支架存在于许多天然产物和生物活性化合物中。本文报道了一种新的铜催化烯烃分子内碳醚化合成双环四氢呋喃。该反应涉及铜催化的醇与未活化烯烃的分子内加成,随后芳基 CH 官能化提供 CC 键。机理研究表明,涉及一个主要的碳自由基中间体,芳环上的自由基加成是可能的 CC 键形成机制。初步的催化对映选择性反应很有希望(高达 75% ee),并提供证据表明铜参与烯烃加成步骤,可能是通过顺式氧化铜机制。催化对映选择性烯烃碳醚化反应很少见,未来将这种新方法发展为高度对映选择性工艺是有希望的。在机理研究过程中,还制定了烯烃加氢醚化的方案。
Electrocatalytic Oxidative Hydrofunctionalization Reactions of Alkenes via Co(II/III/IV) Cycle
Here we disclose a general Co(II/III/IV) electrocatalytic platform for alkene functionalization. Driven by electricity, a set of the oxidative hydrofunctionalization reactions via hydrogen atom transfer were demonstrated without the need for stochiometric chemical oxidants. The scope of the reactions encompasses hydroalkoxylation, hydroacyloxylation, hydroarylation, semipinacol rearrangement, and deallylation
Effects of ligands on the migratory insertion of alkenes into rhodium–oxygen bonds
作者:Casseday P. Richers、Sven Roediger、Victor Laserna、John F. Hartwig
DOI:10.1039/d0sc04402d
日期:——
Migratory insertions of olefins into metal–oxygen bonds are elementary steps of important catalytic processes, but well characterised complexes that undergo this reaction are rare, and little information on the effects of ancillary ligands on such reactions has been gained. We report a series of alkoxo alkene complexes of rhodium(I) that contain a range of bidentate ligands and that undergo insertion of the
烯烃迁移插入金属-氧键是重要催化过程的基本步骤,但经历该反应的良好表征的配合物很少见,并且关于辅助配体对此类反应的影响的信息很少。我们报道了一系列铑( I )的烷氧基烯烃配合物,其含有一系列二齿配体并且经历了烯烃的插入。我们的结果表明,含有较少供电子辅助配体的配合物比含有较多供电子辅助配体的配合物反应更快,并且具有较大咬角的配体的配合物比具有较小咬角的配体反应更快。外部添加的配体对反应有多种影响,包括抑制产物中的烯烃异构化和加速产物从具有小咬角的辅助配体复合物中的置换。补充计算研究有助于阐明这些插入过程的细节。