Oxygen and nitrogen-containing heterocycles are ubiquitous in bioactive compounds of both natural and synthetic origin. Methods for their efficient synthesis impact drug discovery and chemical biology. A suite of heterocycle-forming reactions enabled by copper-catalyzed additions of heteroatoms to alkenes and related carbon-carbon double bonds will be presented. First discovered as copper-promoted reactions, their development into catalytic and enantioselective processes subsequently ensued. Mechanistic investigations support stereocontrolled copper(II) promoted alkene additions as well the creation of powerful organic radicals that can participate in atom transfer, cross-coupling and C-H functionalization steps.