An approach to construct enantiopure complex natural product-like frameworks, including the first reported synthesis of a C17 oxygenated taxoid scaffold, is presented. A palladium-catalyzed C–C activation/cross-coupling is utilized to access these structures in a short sequence from (+)-carvone; the scope of this reaction is explored.
The Selective Cross-Coupling of Secondary Alkyl Zinc Reagents to Five-Membered-Ring Heterocycles Using Pd-PEPPSI-IHept<sup>Cl</sup>
作者:Bruce Atwater、Nalin Chandrasoma、David Mitchell、Michael J. Rodriguez、Matthew Pompeo、Robert D. J. Froese、Michael G. Organ
DOI:10.1002/anie.201503941
日期:2015.8.10
leads to β‐hydride elimination. Whereas catalysts have been reported that provide decent selectivity for the expected (non‐rearranged) cross‐coupled product with aryl or heteroaryl oxidative‐addition partners, none have shown reliable selectivity with five‐membered‐ring heterocycles. In this report, a new, rationally designed catalyst, Pd‐PEPPSI‐IHeptCl, is demonstrated to be effective in selective
Scope and Mechanism of Palladium-Catalyzed Amination of Five-Membered Heterocyclic Halides
作者:Mark W. Hooper、Masaru Utsunomiya、John F. Hartwig
DOI:10.1021/jo0266339
日期:2003.4.1
Detailed studies have been conducted to determine the activity of palladium catalysts for the amination of five-membered heterocyclic halides and to determine the factors that control the scope of this reaction. Palladium-catalyzed aminations of the electron-rich furanyl, thiophenyl, and indolyl halides and of the related 2-halogenated thiazoles, benzimidazole, and benzoxazole have been shown to occur
Pd-PEPPSI-IHept<sup>Cl</sup>
: A General-Purpose, Highly Reactive Catalyst for the Selective Coupling of Secondary Alkyl Organozincs
作者:Bruce Atwater、Nalin Chandrasoma、David Mitchell、Michael J. Rodriguez、Michael G. Organ
DOI:10.1002/chem.201603603
日期:2016.10.4
Dichloro[1,3‐bis(2,6‐di‐4‐heptylphenyl)imidazol‐2‐ylidene](3‐chloropyridyl)palladium(II) (Pd‐PEPPSI‐IHeptCl), a new, very bulky yet flexible Pd–N‐heterocyclic carbene (NHC) complex has been evaluated in the cross‐coupling of secondary alkylzinc reactants with a wide variety of oxidativeaddition partners in high yields and excellent selectivity. The desired, direct reductive elimination branched products
A Synthetic Route to Chiral Tetrahydropyrroloindoles via Ring Opening of Activated Aziridines with 2-Bromoindoles Followed by Copper-Catalyzed C–N Cyclization
作者:Masthanvali Sayyad、Abhijit Mal、Imtiyaz Ahmad Wani、Manas K. Ghorai
DOI:10.1021/acs.joc.6b01049
日期:2016.8.5
A new syntheticroute to nonracemic tetrahydropyrrolo[2,3-b]indoles has been developed via SN2-type ringopening of enantiopure N-activated aziridines with 2-bromoindoles followed by copper-catalyzed C–Ncyclization. A series of N-activated aziridines and 2-bromoindole derivatives with different substitution patterns were studied to afford the corresponding tetrahydropyrrolo[2,3-b]indoles in good yields
通过用2-溴吲哚将对映纯N活化的氮丙啶的S N 2型开环,然后进行铜催化的CN环化,已开发出一种新的合成非外消旋四氢吡咯并[2,3- b ]吲哚的途径。研究了一系列具有不同取代模式的N活化氮丙啶和2-溴吲哚衍生物,从而以良好的收率和优异的ee(高达99%)提供了相应的四氢吡咯并[2,3- b ]吲哚。高度取代的四氢吡咯并[2,3- b ]吲哚由对映体纯的反式-二取代的氮丙啶合成为单个立体异构体(de,ee> 99%)。