Directed Regioselective Carbometallation of 1,2‐Dialkyl‐Substituted Cyclopropenes
作者:Yair Cohen、Ilan Marek
DOI:10.1002/anie.202111382
日期:2021.12.6
The copper-catalyzedcarbomagnesiation reaction of cyclopropenes is a well-established method for the synthesis of stereodefined cyclopropanes. All existing reports to date proceeded towards the formation of the electronically more stable organometallic intermediate. Herein we report a regioselective addition to 1,2-dialkyl-substituted cyclopropene possessing a tethered directing group to direct the
A new, highly potent activator for molybdenumhexacarbonyl and 2-fluorophenol is described. An “instant” catalyst formed in situ from molybdenumhexacarbonyl and 2-fluorophenol shows high activity for cross- and ring-closing alkyne metathesis reaction. The use of 2-fluorophenol can be combined with other activation methods to allow alkyne metathesis at relatively low temperature (80 °C).
Mild Niobium-Catalyzed [2 + 2 + 2] Cycloaddition of Sila-triynes: Easy Access to Polysubstituted Benzosilacyclobutenes
作者:Cédric Simon、Muriel Amatore、Corinne Aubert、Marc Petit
DOI:10.1021/ol503663k
日期:2015.2.20
A new and efficient synthesis of highly sensitive benzosilacyclobutenes has been developed. For the first time, these compounds can be synthesized in very high yields by a mild, unprecedented intramolecular niobium-catalyzed [2 + 2 + 2] cycloaddition of easily accessible tetrasubstituted sila-triynes. An easy access to highly functionalized benzosilacyclobutenes enlarging the number of potential applications in organic and material chemistry is described.