Two Roads to Arylstannanes: Arynes and Stannylpotassiums

Arylstannanes are versatile organometallic reagents, and efficient methods for synthesizing them remain in demand. We report two approaches that expand this chemistry. First, aryne insertion reactions into Sn-F, Sn-CN, Sn-alkynyl, and Sn-aryl bonds furnish fluoro-, cyano-, alkynyl-, and aryl-substituted arylstannanes with high regioselectivity and broad functional group tolerance. Mechanistic studies reveal a decisive role of fluoride in activating organostannanes and promoting Cu-assisted transmetalation. Second, we introduce a convenient protocol for generating stannylpotassium species from silylstannanes and t-BuOK. The stannylpotassium reagents, featuring fully ionic Sn-K bonds, exhibit superior nucleophilicity and smoothly convert diverse aryl halides, including sterically hindered and heteroaryl substrates, into arylstannanes at room temperature under transition metal-free conditions. Together, these aryne- and stannylpotassium-based strategies provide operationally simple and general routes to diverse arylstannanes of high synthetic utility.