Interligand Interactions Dictate the Regioselectivity of<i>trans</i>-Hydrometalations and Related Reactions Catalyzed by [Cp*RuCl]. Hydrogen Bonding to a Chloride Ligand as a Steering Principle in Catalysis
作者:Stephan M. Rummelt、Karin Radkowski、Dragoş-Adrian Roşca、Alois Fürstner
DOI:10.1021/jacs.5b01475
日期:2015.4.29
mode in the presence of [Cp*Ru(MeCN)3]PF6 (1) as the catalyst; however, the regioselectivity is often poor with unsymmetrical substrates. This problem can be solved upon switching to a catalyst comprising a [Ru-Cl] bond, provided that the acetylene derivative carries a protic functional group. The R3M unit is then delivered with high selectivity to the alkyne-C atom proximal to this steering substituent
Iron-Catalyzed Cross-Coupling of 1-Alkynylcyclopropyl Tosylates and Related Substrates
作者:Daniel J. Tindall、Helga Krause、Alois Fürstner
DOI:10.1002/adsc.201600357
日期:2016.7.28
1‐Alkynylcyclopropyl tosylates react with alkylmagnesium halides in the presence of catalytic ferric acetylacetonate [Fe(acac)3] under net propargylic substitution; allene formation, which is the prevalent reactivity mode of propargylic substrates otherwise, was noticed as a side reaction only when branched alkyl‐ or aryl‐Grignard reagents were used. These transformations represent the first successful iron‐catalyzed
A convenient new method was developed to prepare two types of vinyl cyclopropane derivatives through gold-catalyzed cyclization of 1-alkynyl cyclopropyl tert-butyl carbonates 2. Different from the previous reported 5-exo-dig route, the 6-endo-dig addition is the preferred pathway to provide six-membered cyclized carbonates. Two factors, including stereoelectronic effect and steric effect might affect
A new synthetic route was developed via the nucleophilic addition of lithium alkynylide to 1-arylsulfonyl cyclopropanol 1 to afford 1-alkynyl cyclopropanol, which then reacted with aryl iodide to construct trisubstituted cross-conjugated dienones through a palladium-catalyzed process, where the key steps included the regioselective carbopalladation of arylpalladium(II) intermediate across the triple