Palladium-Catalyzed Carbonylative Cyclization of Unsaturated Aryl Iodides and Dienyl Triflates, Iodides, and Bromides to Indanones and 2-Cyclopentenones
作者:Steve V. Gagnier、Richard C. Larock
DOI:10.1021/ja0212009
日期:2003.4.1
carbonylative cyclization is particularly effective on substrates that contain a terminal olefin. The proposed mechanism for this annulation includes (1) Pd(OAc)(2) reduction to the active palladium(0) catalyst, (2) oxidative addition of the organichalide or triflate to Pd(0), (3) coordination and insertion of carbon monoxide to produce an acylpalladium intermediate, (4) acylpalladation of the neighboring
Particular attention has been given to the novel synthesis of the optically active spiro carbon center by a stereospecific rearrangement of optically active benzofuzed-trans-epoxy acylates leading to spirocyclopentane-1,1'-indane systems. This method is quite useful for the construction of an optically active spiro compound and was applied to the synthesis of the optically pure CDEF-ring unit of 1. Cycloaddition
Palladium-catalyzed intramolecular 5-endo–trig oxidative Heck cyclization: a facile pathway for the synthesis of some sesquiterpene precursors
作者:Devalina Ray、Sunanda Paul、Sulagna Brahma、Jayanta. K. Ray
DOI:10.1016/j.tetlet.2007.09.052
日期:2007.11
An efficient and convenient method for the construction of substituted cyclopentenones via palladium-catalyzed intramolecular 5-endo–trig oxidative cyclization has been introduced as a powerful new strategy for the synthesis of sesquiterpenes.
Interrupted Nazarov Reactions Using Dichlorocyclopropanes: A Novel Mode of Arene Trapping
作者:Tina N. Grant、F. G. West
DOI:10.1021/ol7015669
日期:2007.9.1
2-Siloxy-2-alkenyl-1,1-dichlorocyclopropanes with aryl-terminated side chains undergo silver-assisted electrocyclic opening/Nazarov cyclization. The resulting 2-siloxycyclopentenyl cations are intercepted by the pendant arenes to furnish tricyclic adducts in moderate to good yields. In cases where the arene trap was tethered through the cyclopropane unit, a new mode of trapping occurred to generate unique bridged carbon frameworks.