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. Author manuscript; available in PMC: 2011 Jun 23.
Published in final edited form as: J Am Chem Soc. 2010 Jun 23;132(24):8419–8427. doi: 10.1021/ja101851v

Table 5.

Optimization of Arylbromination Reaction

graphic file with name nihms210777t55.jpg
Entry Solvent Temperature Concentration Yield
CuBr2a 		28a :
28ba 		Yield
NBSa 		28a :
28ba
1 Dioxane 25 °C 0.032 M 29% 1 : >20 19% 1 : >20
2 C6H6 25 °C 0.032 M 24% 1 : 13 8% 1 : >20
3 AcOH 25 °C 0.032 M 16% 1 : >20 0% ndb
4 CH2Cl2 25 °C 0.032 M 27% 1 : >20 6% 1 : >20
5 Et2O 25 °C 0.032 M 46% 1 : >20 8% 1 : >20
6 Et2O −78 °C to 25 °C 0.032 M 82% 1 : >20 ndb ndb
7 THF 25 °C 0.032 M 25% 1 : >20 11% 1 : >20
8c THF −78 °C to 25 °C 0.032 M 49% (17%) 3 : 1 ndb ndb
9c THF −78 °C to 25 °C 0.064 M 50% (5%) 10 : 1 ndb ndb
10c THF −78 °C to 25 °C 0.128 M 80% (20%) 10 : 1 ndb ndb
a

Yield and ratio of isomers determined by 1H NMR spectroscopic analysis of crude reaction mixture. The yield of 29 is shown in parentheses where applicable.

b

nd = not determined.

c

1.9 equiv of PhSnBu3.