as natural products, pharmaceuticals, and π-conjugated systems are at the heart of constructing and modifying organic molecules, whereby the selectivity and predictability are of the utmost importance. Herein, we report the highly C3-selective C–H borylation of strychnine along with olefin isomerization, catalyzed by an iridium complex with a diphosphine ligand. This method enabled us to rapidly produce
Gold-Catalysed Oxyarylation of Styrenes and Mono- and<i>gem</i>-Disubstituted Olefins Facilitated by an Iodine(III) Oxidant
作者:Liam T. Ball、Guy C. Lloyd-Jones、Christopher A. Russell
DOI:10.1002/chem.201103061
日期:2012.3.5
1‐Hydroxy‐1,2‐benziodoxol‐3(1H)‐one (IBA) is an efficient terminal oxidant for gold‐catalysed, three‐component oxyarylation reactions. The use of this iodine(III) reagent expands the scope of oxyarylation to include styrenes and gem‐disubstituted olefins, substrates that are incompatible with the previously reported Selectfluor‐based methodology. Diverse arylsilane coupling partners can be employed
Addition and Cyclization Reactions in the Thermal Conversion of Hydrocarbons with an Enyne Structure, 5. High-Temperature Ring Closures of 1,3-Hexadien-5-ynes to Naphthalenes – Competing Reactions via Isoaromatics, Alkenylidene Carbenes, and Vinyl-type Radicals
2-ethynylstyrenes 7a–c were subjected to high-temperature pyrolysis. The cycloisomerization products isolated suggest that these are formed by three competing processes: by (i) an electrocyclic or a molecule-induced, (ii) an alkenylidenecarbene controlled, and (iii) a radical-controlled ring-closure process. To estimate the relative importance of these three reactions here mentioned, the substrates have
Cobalt-Catalyzed Defluorosilylation of Aryl Fluorides via Grignard Reagent Formation
作者:Soobin Lim、Hyungdo Cho、Jongheon Jeong、Minjae Jang、Hyunseok Kim、Seung Hwan Cho、Eunsung Lee
DOI:10.1021/acs.orglett.0c02752
日期:2020.9.18
cheap electrophilic silicon source with magnesium. This method is compatible with various silicon sources and can be operated under aerobic conditions. Mechanistic studies support the in situ formation of a Grignard reagent, which is captured by the electrophilic silicon source.
Lewis Acid-Mediated Carboxylation of Aryl- and Allylsilanes with Carbon Dioxide
作者:Tetsutaro Hattori、Yutaka Suzuki、Sotaro Miyano
DOI:10.1246/cl.2003.454
日期:2003.5
Aryl- and allylsilanes are carboxylated with CO2 with the aid of aluminum-based Lewis acids, to give aromatic and β,γ-unsaturated carboxylic acids in fair to good yields, respectively. Formation of the former is rationalized by an aromatic electrophilic substitution by CO2 activated by the Lewis acid, while the latter a nucleophilic addition of in situ-generated allylaluminum species to CO2.