Transition-Metal Catalyzed Unimolecular Fragment Couplings

As alternative strategy to transition metal-catalyzed cross- coupling, unimolecular fragment coupling (UFC) is defined as the reaction format, in which the atom(s) in the middle of the molecule is extruded, and the remaining fragments are coupled. UFC is a potentially powerful strategy, as the starting materials are readily available through well- established methods, and the key bond formation event proceeds in an intramolecular manner, thereby allowing for high chemo- and stereoselectivity. Herein, we overview UFC reactions of ketones, esters, amides and acylsilanes with the elimination of carbon monoxide, carbon dioxide, isocyanate and oxygen atom.