An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Many useful transition-metal-catalyzed reactions depend on the migratory insertion of an alkyne into a metal–carbon bond. Steric effects, electronic effects, and coordinating directing groups have all been shown to control product distributions in reactions in which this is the regioselectivity-determining step. This study describes how both steric and electronic parameters influence regioselectivity within a previously disclosed Ni-catalyzed indenone synthesis reaction. Steric repulsion determines the overall sense of regioselectivity, and to some extent the magnitude, while electronic effects can also significantly alter the magnitude of the observed regioselectivity. The relationship between alkyne insertion regioselectivity and the electronic character of the migrating aryl group is demonstrated via comparisons with established electronic substituent constants (σ+ values). These observations will aid in the understanding and development of other regioselective alkyne carbofunctionalization reactions.
