Sequential Conia-ene-type cyclization and Negishi coupling by cooperative functions of B(C6F5)3, ZnI2, Pd(PPh3)4 and
Min Cao1, Ahmet Yesilcimen1, Soumil Prasad1
1Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA. wasa@bc.edu.
Abstract:
We disclose a method for sequential Conia-ene-type cyclization/Negishi coupling for the union of alkynyl ketones and aryl iodides. This process is promoted through cooperative actions of Lewis acidic B(C6F5)3, ZnI2, Pd-based complex, and a Brønsted basic amine. The three Lewis acid catalysts with potential overlapping functions play their independent roles as activators of carbonyl group, alkyne moiety, and alkenyl zinc intermediate, respectively. A variety of 1,2,3-substituted cyclopentenes can be synthesized with high efficiency.
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