Intermolecular Pauson-Khand-Type Reaction of Vinyl Iodides with Alkynes and a CO Surrogate
Philip Boehm1, Elliott H Denton1, Joel Wick1
1ETH Zürich, Vladimir-Prelog-Weg 3, HCI, 8093 Zürich, Switzerland.
Abstract:
A strategy for the palladium-catalyzed intermolecular synthesis of polysubstituted cyclopentenones is reported. The three-component reaction utilizes vinyl iodides and internal alkynes to form the carbon framework of the cyclopentenone with Cr(CO)6 serving as an easy to handle, solid CO surrogate, and a hydrosilane as a hydride source. We demonstrate the scope of the reaction which includes a wide range of functional groups. The reaction is regioselective, with the use of linear or branched vinyl iodides resulting in the α- or β-substituted cyclopentenones, respectively. Further, we show that a two-step sequence from commercially available alkynes can be used to generate cyclopentenone products via formation of the vinyl iodide and subsequent Pauson-Khand-type reaction.
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