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. Author manuscript; available in PMC: 2013 Jul 25.
Published in final edited form as: J Am Chem Soc. 2012 Jul 5;134(29):12149–12156. doi: 10.1021/ja3034075

Table 5.

Catalytic asymmetric carboetherificationsa

graphic file with name nihms391705u3.jpg
entry substrate CuX2 yield (%) dr (16:17)b ee (%)c
1 15a, R1 = Ph, R2 = H, Ar = Ph Cu(eh)2 62 >20:1 <5
2 15a Cu(OTf)2 89 2:1 30, 67
3 15c, R1 = Ph, R2 = H, Ar = 4-Cl-C6H4 Cu(OTf)2 77 2:1 32, 60
4 15d, R1 =Ph, R2 = Ph, Ar = Ph Cu(OTf)2 89 -- ca 75%
5 15e, R1 = Ph, R2 = Ph, Ar = 4-Cl-C6H4 Cu(OTf)2 85 -- nd
a

Reaction conditions: CuX2 (0.376 mmol) and (R,R)-Ph-box (0.0470 mmol) were combined in PhCF3 (0.6 mL) and heated in a sealed tube for 2 h. Alcohol 15 (0.188 mmol) in 0.9 mL PhCF3, K2CO3, (0.188 mmol) and MnO2 (0.564 mmol) were added and the reaction was stirred at 100 °C in a sealed tube for 24 h.

b

Substrates are racemic or achiral.

c

Isolated yield after flash chromatography on SiO2.

d

Ratio determined by analysis of the 1H NMR spectra of the crude reaction mixture. c Enantiomeric excess determined by chiral HPLC. Nd = not determined. Enantiomers could not be separated on chiral HPLC or gc.