Facile ring-closure cyclization of arenes by nucleophilic C-alkylation reaction in ionic liquid
作者:Dong Jin Hong、Dong Wook Kim、Dae Yoon Chi
DOI:10.1016/j.tetlet.2009.10.065
日期:2010.1
cyclization by nucleophilic C-alkylation was achieved with various halo- and alkanesulfonyloxyalkyl aromatic compounds in high yields with minimal byproducts using ILs as the reactionmedia in the absence of any catalyst. For example, the cyclization of 2-(3-methanesulfonyloxy-propoxy)naphthalene (1a) to 2,3-dihydro-1H-naphtho[2,1-b]pyran (2) in IL [bmim][PF6] proceeded selectively at 150 °C for 24 h in
描述了一种使用离子液体(IL)进行六元闭环环化的新颖合成方法。在不使用任何催化剂的情况下,使用ILs作为反应介质,使用各种卤代和链烷磺酰氧基烷基芳族化合物,可以通过高收率和副产物最少的副产物,通过亲核C-烷基化实现闭环环化。例如,在IL [bmim] [PF 6 ]中将2-(3-甲磺酰氧基-丙氧基)萘(1a)环化为2,3-二氢-1 H-萘[ 2,1 - b ]吡喃(2)。在150°C下选择性地进行24小时,产率为85%。
Intramolecular Hydroarylation of Alkynes Catalyzed by Platinum or Gold: Mechanism andendo Selectivity
作者:Cristina Nevado、Antonio M. Echavarren
DOI:10.1002/chem.200401069
日期:2005.1
The cyclization of differently substituted aryl alkynes with PtII or AuI catalysts proceeds by endo-dig pathways. When AgI was used to generate reactive cationic AuI catalysts, 2H-chromenes dimerize to form cyclobutane derivatives by a AgI-catalyzed process. A DFT study on the cyclization mechanism shows a kinetic and thermodynamic preference for 6-endo-dig versus 5-exo-dig cyclizations in PtII-catalyzed
Alcohol Etherification via Alkoxy Radicals Generated by Visible-Light Photoredox Catalysis
作者:Alexandra R. Rivero、Peter Fodran、Alica Ondrejková、Carl-Johan Wallentin
DOI:10.1021/acs.orglett.0c03058
日期:2020.11.6
A mechanistically divergent method is described that, employing a commercially available hypervalent iodine(III) reagent, generates alkoxy radicals from 1°, 2°, and 3° alcohols and allows their use in the functionalization of C(sp3)–H and C(sp2)–H bonds. This visible-light photoredox catalysis produces alkyl ethers via 1,5/6-hydrogen atom transfer or aryl ethers via 1,5-addition. This mild methodology