Copper Photocatalyzed Divergent Access to Organic Thio- and Isothiocyanates

Abstract

We disclose a copper-photocatalyzed strategy that enables selective access to organic thiocyanates and isothiocyanates using benzylic thiocyanates as ATRA reagents. The electronic nature of the aromatic system is a crucial factor defining the outcome of the reaction for forging either the kinetic C-S or the thermodynamic C-N bonds. Mechanistic investigations support a radical pathway initiated by a reductive C-S bond cleavage of the substrates followed by a divergent inner-/outer-sphere interaction with copper depending on the electronic density of the formed intermediates. The developed protocol proceeds with high regio- and chemoselectivity and can also be applied for late-stage functionalization of bioactive molecules. The utility of the products is highlighted by their facile conversion to several building blocks that are relevant to organic synthesis.