Switchable organocatalytic enantioselective sulfenocyclization of cyclohexadienes enabling chemodivergent access to chiral bicyclo[m.n.1] ring systems

The precise control over regio- and stereoselectivity from the same substrate represents a significant challenge in organic chemistry. Herein, a switchable organocatalytic enantioselective carbosulfenylation/sulfenolactonization of cyclohexa-1,4-dienes to access the chiral bicyclo[m.n.1] ring systems, which are the critical core skeleton of many important natural products and biologically active compounds, is achieved. By simply tuning the substituent of the sulfenylating agent, a series of synthetically challenging chiral bridged bicyclo[3.3.1]nonanes and 2-oxabicyclo[3.2.1]octanes bearing three consecutive stereocenters are obtained with good yields and excellent enantioselectivities (up to 94% yield and 97% ee). Furthermore, the initial investigation of the bicyclic derivative as a chiral ligand in metal catalysis is also conducted. Our findings offer a version of switchable divergent asymmetric synthesis in which different products can be controllably generated from an identical set of substrates by simply adjusting reaction parameters.