Gold and Brønsted Acid Catalyzed Hydride Shift onto Allenes: Divergence in Product Selectivity
摘要:
A series of allenyl ethers can be transformed into various fused or spiro tetrahydrofurans and tetrahydropyrans following a hydride shift/cyclization sequence. A divergence in product selectivity, which depends on the nature of the catalyst used (Au(I) complex or Bronsted acid), was observed.
Photo-Mediated Decarboxylative Giese-Type Reaction Using Organic Pyrimidopteridine Photoredox Catalysts
作者:Firas El-Hage、Christopher Schöll、Jola Pospech
DOI:10.1021/acs.joc.0c01955
日期:2020.11.6
The decarboxylativeGiese-typereaction offers a versatile methodology for the radical alkylation of electron-deficient alkenes. Photo-mediated variants often require a pre-activation of carboxylicacids and/or employment of costly transition-metal photocatalysts. Herein, we present a metal-free photocatalyzed decarboxylativeGiese-type addition to electron-deficient alkenes using pyrimidopteridine
C−H Bond Functionalization via Hydride Transfer: Direct Coupling of Unactivated Alkynes and sp<sup>3</sup> C−H Bonds Catalyzed by Platinum Tetraiodide
作者:Paul A. Vadola、Dalibor Sames
DOI:10.1021/ja906480w
日期:2009.11.18
We report a catalytic intramolecular coupling between terminal unactivated alkynes and sp(3) C-H bondsvia through-space hydride transfer (HT-cyclization of alkynes). This method enables one-step preparation of complex heterocyclic compounds by alpha-alkenylation of readily available cyclic ethers and amines. We show that PtI(4) is an effective Lewis acid catalyst for the activation of terminal alkynes
Hydroalkylation of Alkynyl Ethers via a Gold(I)-Catalyzed 1,5-Hydride Shift/Cyclization Sequence
作者:Igor Dias Jurberg、Yann Odabachian、Fabien Gagosz
DOI:10.1021/ja9100134
日期:2010.3.17
A series of alkynyl ethers react with an electrophilic gold(I) catalyst to produce a range of structurally complex spiro or fused dihydrofurans and dihydropyrans via a 1,5-hydride shift/cyclization sequence. This hydroalkylation process, which is performed under practical experimental conditions, can be applied to terminal as well as ester-substituted alkynes. It allows the efficient conversion of
一系列炔基醚与亲电子金 (I) 催化剂反应,通过 1,5-氢化物转移/环化序列产生一系列结构复杂的螺或稠合二氢呋喃和二氢吡喃。这种在实际实验条件下进行的加氢烷基化过程可应用于末端和酯取代的炔烃。它允许通过将乙烯基金物质亲核加成到氧鎓中间体上,将二级或三级 sp(3) CH 键有效转化为新的 CC 键。形成新的五元或六元环的环异构化过程的立体选择性似乎取决于空间因素和炔烃取代模式。
Gold and Brønsted Acid Catalyzed Hydride Shift onto Allenes: Divergence in Product Selectivity
作者:Benoit Bolte、Fabien Gagosz
DOI:10.1021/ja202336p
日期:2011.5.25
A series of allenyl ethers can be transformed into various fused or spiro tetrahydrofurans and tetrahydropyrans following a hydride shift/cyclization sequence. A divergence in product selectivity, which depends on the nature of the catalyst used (Au(I) complex or Bronsted acid), was observed.