Skip to main content
. Author manuscript; available in PMC: 2013 May 1.
Published in final edited form as: Chem Sci. 2012 May;3(5):1589–1593. doi: 10.1039/C2SC01134D

Table 1.

Catalyst screening for enantioselective cyclopropanation of styrene with ethyl α-diazobutanonate: Rh2(S-BPTTL)4= dirhodium(II) tetrakis[N-2,3-naphthaloyl-(S)-tert-leucinate]; Rh2(S-NTTL)4= dirhodium(II) tetrakis[N-1,8-naphthaloyl-(S)-tert-leucinate]; Rh2(S-TBPTTL)4= dirhodium(II) tetrakis[N-tetrabromophthaloyl-(S)-tert-leucinate];

graphic file with name nihms390009u1.jpg;
Rh(II) Catalyst Solvent %yda drb %eec
Rh2(S-PTTL)4 Hexanes 95 92:8 79
Rh2(S-BPTTL)4 Toluene 80 88:12 73
Rh2(S-NTTL)4 Toluene 61 75:25 45
Rh2(S-TBPTTL)4 CH2Cl2 6 97:3 11
Rh2(S-TBPTTL)4 Toluene 10 88:12 16
Rh2(S-TBPTTL)4 Hexanes 23d 84:16 16
Rh2(TPA)(S-PTTL)3 Toluene 66 95:5 81
Rh2(TPA)(S-PTTL)3 Hexanes 91 96:4 88
a

Isolated yields.

b

Measured by GC.

c

Measured by chiral HPLC.

d

Run at −60 °C for 2 hours. No reaction occurred at −78 °C.