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