Catalyst-free 1,2-carboboration of ynamides is presented. Readily available aryldichloroboranes react with alkyl- or aryl-substituted ynamides in high yields with complete regio- and stereoselectivity to valuable β-boryl-β-alkyl/aryl α-aryl substituted enamides which belong to the class of trisubstituted alkenylboronates. The 1,2-carboboration reaction is experimentally easy to conduct, shows high functional group tolerance and broad substrate scope. Gram-scale reactions and diverse synthetic transformations convincingly demonstrate the synthetic potential of this method. The reaction can also be used to access 1-boraphenalenes, a class of boron-doped polycyclic aromatic hydrocarbons.
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| http://dx.doi.org/10.1002/anie.202107647 | DOI Listing |
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