Carbogallation of Alkynes Using Gallium Tribromide and Silyl Ketene Acetals and Synthetic Application to Cross‐Coupling with Aryl Iodides

Try substituted alkynes with GaBr3: The regio- and stereoselective carbogallation of alkynes has been achieved by a simple treatment of GaBr3, alkynes, and ketene silyl acetals. The produced alkenylgallium compounds can be used for the synthesis of selective trisubstituted alkenes through successive cross-coupling with aryliodides (see scheme). The usability of the carbogallation was presented by the total synthesis of meroterpenoid nodosol, which was extracted from the seagrass Cymodocea nodosa.