2 research outputs found
Transition-Metal-Free, Atom- and Step-Economic Synthesis of Aminoketopyrrolizines from Benzylamine, Acylethynylpyrroles, and Acylacetylenes
A concise, atom-economic
strategy for the synthesis of pyrrolizines
with amino and keto substituents has been developed. It includes the
following key steps: (i) the base-catalyzed (K<sub>3</sub>PO<sub>4</sub>/DMSO) addition of a benzylamine to 2-acylethynylpyrroles and (ii)
noncatalyzed addition of enaminones obtained to the triple bond of
acylacetylenes followed by intramolecular cyclization of the intermediate
pentadiendiones thus formed to the target 1-(benzylamino)-2-acyl-3-methylenoacylpyrrolizines
Expedient Strategy for the Synthesis of 5-Acylethynylpyrrole-2-carbaldehydes
<div><p></p><p>5-Acylethynylpyrrole-2-carbaldehydes have been synthesized from the protected pyrrole-2-carbaldehydes by their transition-metal-free topochemical mechanoactivated ethynylation with acylbromoacetylenes in a solid Al<sub>2</sub>O<sub>3</sub> medium (room temperature, 6 h, 41–54% yields).</p></div