Cyclization by Catalytic Ruthenium Carbene Insertion into C sp 3H Bonds
作者:Fermín Cambeiro、Susana López、Jesús A. Varela、Carlos Saá
DOI:10.1002/anie.201107344
日期:2012.1.16
A novel tandem Ru‐catalyzed carbene addition to terminal alkynes/insertion into CHbonds in alkynyl acetals, ethers, and amines has been accomplished under mild reaction conditions (see scheme; TMS=trimethylsilyl). This cascade provides an efficient approach to form complex spiro and fused bicyclic structures by 1,5‐ and 1,6‐hydride shift/cyclization sequences from vinylcarbene Ru intermediates.
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。
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