Stereospecific Stille Cross-Couplings Using Mn(II)Cl2

Cross-coupling reactions are a staple in organic synthesis, especially for C–C bond formation with sp- and sp2-carbon electrophiles. In recent years, the range of accessible C–C bonds has been extended to stereogenic centers which expedites access to greater molecular complexity. However, these reactions predominantly depend upon late transition metal (LTM) catalysts whose cost, toxicity, and/or environmental impact have come under increasing scrutiny and governmental regulation. Here, we report Mn­(II)­Cl2 complexes alone, or with assistance from copper, catalyze the stereospecific cross-coupling of α-alkoxyalkylstannanes with organic electrophiles with complete retention of configuration.