Enhancing the generality of the intramolecular palladium-catalyzed [3+ 21 cycloaddition involving tri-methylenemethane complexes as reactive intermediates is possible by incorporation of acyl substituents on the TMM unit. Such substituted TMM-PdL2 species greatly expand the scope such that bicyclo [3.3. 0] octyl, bicyclo [4.3. 0] nonyl, and bicyclo [5.3. 0] decyl ring systems all can be created. Furthermore, the acyl-TMM chemistry ...