パラジウム触媒を用いたα，β―不飽和カルボニル化合物と分子内不飽和結合の連続的環化・カップリング反応

抄録

A palladium-catalyzed method for cyclizations of electron-deficient alkenes with tethered unsaturation in the presence of organoboron reagents was developed. Considerable flexibility in the structure of each reactive component was observed. Enals, enones, alkylidene malonates, and nitroalkenes participated as the electron-deficient alkene; alkynes and 1,2-dienes participated as the tethered unsaturation; and a variety of sp2 and sp3-hybridized organoboron reagents, including those that possess beta-hydrogens, participated as the nucleophilic component. Substrate structure, organoboron structure, ligand structure, and reaction solvent all played a significant role in the cyclization efficiency. Of particular synthetic significance was the opportunity to prepare either E or Z tri- or tetrasubstituted alkenes from a common alkyne. A discussion of probable mechanisms is provided.

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