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. Author manuscript; available in PMC: 2010 Sep 2.
Published in final edited form as: J Am Chem Soc. 2009 Sep 2;131(34):12406–12414. doi: 10.1021/ja904604x

Table 1.

Optimization of Aldol Reactiona

graphic file with name nihms-137472-t0018.jpg
entry solvent R-BINOL (mol %) additive yield (%)b ee (%)c
1 THF 8 4 Å MS 50 73d,e
2 THF 8 4 Å MS 53 71d
3 THF 10 4 Å MS 60 78d,e
4 toluene 10 4 Å MS 30 71
5 CH2Cl2 10 4 Å MS — —
6 THF 10 3 Å MSf 65 68
7 THF 10 3 Å MS 66 63
8 THF 10 3 Å MSf,g 65 81
9 THF 10 4 Å MSg 57 74
10 THF 15 4 Å MSg 66 80
11 THF 10 4 Å MS 63 88
12 THF 15 4 Å MS 64 60
a

Reactions performed under N2 at 0.17 M (precomplexation concentration 0.53 M) with Ti(i-OPr)4 and ligand after 60 min, reaction cooled to -78 °C followed by addition of 13 and 14.

b

Isolated yields after column chromatography.

c

Determined by chiral HPLC.

d

precomplexation concentration 0.21 M.

e

Slowly warmed to 23 °C.

f

3 Å MS pellets.

g

Dried in a reduced pressure oven at 145 °C for 2 days.