Fig. 2: Optimization of reaction conditions.
From: Pathway-divergent coupling of alkynes and cyclobutenes through enantioselective cobalt catalysis
a Optimization for enantioselective reductive coupling pathway. b Optimization for enantioselective [2 + 2] cycloaddition pathway. aYield of isolated product. bRatios of regioisomers (rr) and diastereomers (dr) were determined by analysis of 1H NMR spectra of unpurified mixtures. cEnantiomeric ratios (er) were determined by analysis of HPLC spectra. dNot available. eThe reaction was performed with 5.0 mol % CoI2, 5.0 mol % 4h, 2.5 equiv of H2O for 24 h. fThe reaction was conducted with 5.0 mol % CoI2, 5.0 mol % 4h, 25 equiv of H2O for 24 h. gThe reaction was performed in DME. hThe reaction was conducted in the presence of 10 mol % CoBr2. iThe reaction was performed with 10 mol % Zn. 4CzIPN, 1,2,3,5-tetrakis(carbazole-9-yl)−4,6-dicyanobenzene; THF tetrahydrofuran.
