A catalytic [1,3] O‐to‐C rearrangement from enyne‐ethers was developed for the rapid synthesis of diverse bridged bicyclic systems. In this reaction, a vinyl oxonium intermediate, generated in situ from enyne‐ether, was the precursor for the [1,3] O‐to‐C rearrangement. This versatile protocol represents the first example of catalytic [1,3] O‐to‐C rearrangement based on ring‐expansion strategy, enabling
Gold‐Catalyzed Bicyclic Annulations of 2‐Alkynylbenzaldehydes with Vinyldiazo Carbonyls that Serve as Five‐atom Building Units
作者:Antony Sekar Kulandai Raj、Rai‐Shung Liu
DOI:10.1002/anie.201905350
日期:2019.8.5
gold‐catalyzed bicyclic annulations of 2‐alkynyl‐1‐carbonylbenzenes with vinyldiazo ketones that serve as five‐atom building units. The importance of these reactions is to access 4,5‐dihydro‐benzo[g]indazoles, which form the structural cores of various bioactive molecules. According to our mechanistic analysis, we postulate initial [5+4]‐cycloadditions between benzopyrilium intermediates and vinyldiazo
这项工作报告了2-炔基-1-羰基苯与乙烯基重氮酮的金催化双环环化反应,该酮可作为五个原子的构建单元。这些反应的重要性是获得形成各种生物活性分子结构核心的4,5-二氢苯并[ g ]吲唑。根据我们的机理分析,我们假设苯并吡咯中间体与乙烯基重氮酮之间先发生[5 + 4]-环加成反应,然后进行6-π-电环化以实现出色的立体选择性。
Gold‐catalyzed [4+3]‐Annulations of Benzopyriliums with Vinyldiazo Carbonyls to Form Bicyclic Heptatriene Rings with Skeletal Rearrangement
作者:Antony Sekar Kulandai Raj、Rai‐Shung Liu
DOI:10.1002/adsc.202000292
日期:2020.6.15
annulatios are applicable to pyriliums and 3‐alkyl‐2‐diazo‐3‐vinyl esters to increase their reaction significance. We postulate a mechanism involving an initial [4+2]‐cycloaddition between benzopyriliums and 3‐alkyl‐2‐diazo‐3‐vinyl carbonyl species, followed by formation of gold carbenes to induce a ringexpansion and group migrations.
Carbene Transfer - A New Pathway for Propargylic Esters in Gold Catalysis
作者:Tobias Lauterbach、Sabrina Gatzweiler、Pascal Nösel、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/adsc.201300572
日期:2013.9.16
Gold carbenes generated via 1,2‐migration of a propargylic ester group can be transferred over a tethered alkyne. The use of aromatic backbones leads after a 1,7‐carbene transfer to a benzyl‐stabilized carbene as intermediate. A 1,2‐shift of a methyl group delivers vinyl‐substituted β‐naphthol derivatives as the final products.
Gold-Catalyzed Oxidative Cyclizations of 2-Oxiranyl-1-alkynylbenzenes for Diastereoselective Synthesis of Highly Substituted 2-Hydroxyindanones
作者:Rupsha Chaudhuri、Rai-Shung Liu
DOI:10.1002/adsc.201100325
日期:2011.10
We report the gold-catalyzedoxidativecyclizations of 2-oxiranyl-1-alkynylbenzenes into highlysubstituted 2-hydroxyindanone frameworks bearing a tertiary alcohol. Such gold-catalyzed reactions comprise an initial internal redox reaction, sulfoxide oxidation of α-carbonyl gold-carbenoids, followed by gold-catalyzed formal ene reactions on the resulting diketone intermediates.