Fig. 2: Optimization of deborylative alkylation of phenylgermanium trichloride and stepwise functionalization of remaining organoboronic ester.
From: Synthesis of chiral germanium center enabled by poly-deborylative alkylation and desymmetrization
a optimized standard reaction conditions: 1 (0.5 mmol), 2 (2.0 mmol, 4.0 equiv), t-BuOK (2.25 mmol, 4.5 equiv) in THF (0.10 M), 48 h, under argon at 60 °C, all the yield listed were isolated yields. b the yield in bracket was determined by 1H-NMR analysis. c the poly boronic esters could be differentiated by selective transmetallation; see supplementary information synthetic application for experimental details. THF, tetrahydrofuran; KHMDS, potassium bis(trimethylsilyl)amide; DCM, dichloromethane; TBSCl, tert-butyldimethylsilyl chloride; RuPhos, 2-dicyclohexylphosphino-2’,6’-di-i-propoxy-1,1’-biphenyl, CPhos, 2-dicyclohexylphosphino-2’,6’-bis(dimethylamino)−1,1’-biphenyl.
