Pinacol (trimethyhily1) methaneboronate has been prepared from (trimethyhily1) methylmagnesium chloride and has been lithiated with lithium 2, 2, 6, 6- tetramethylpiperidide. Pinacol lithio (trimethylsily1)-methaneboronate with alkyl halides efficiently yields pinacol 1-(trimethylsily1) alkane-1-boronates and with aldehydes or ketones eliminates silicon exclusively to form pinacol 1-alkene-1-boronates, with mostly 2 ...