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. Author manuscript; available in PMC: 2010 Aug 6.
Published in final edited form as: J Am Chem Soc. 2008 Feb 27;130(11):3262–3263. doi: 10.1021/ja710065h

Table 3.

Terminal Alkyne Scope

graphic file with name nihms214576u5.jpg
entry R carbodiimide 3: 4 or 6: 7b yield (%) of 3 or 6c ee (%) of 3 or 6d,e
1 p-Br-C6H4, 1b 2c 16: 1 75 98
2 m-F-C6H4, 1c 2c > 19: 1 77 99
3 3,5-F-C6H3, 1d 2c > 19: 1 66 99
4 p-Ac-C6H4, 1e 2c > 19: 1 78 99
5 p-CF3-C6H4, 1f 2c > 19: 1 68 96
6 m-CN-C6H4, 1g 2c > 19: 1 62 94
7 m-OMe-C6H4, 1h 2c 6.3: 1 69 99
8 m-Me-C6H4, 1i 2c 3.4: 1 61 98
9 2e 8.3: 1 74 98
10 graphic file with name nihms214576t1.jpg, 1j 2c 3.2: 1 58 98
11 2e 7.2: 1 79 97
12 p-OMe-C6H4, 1k 2c 1: 2.8 20 (52)g 99
13 2e 1: 1 37 (36)g 96
14 3,5-F-C6H3, 1d 5 > 19: 1 79 98
15 p-Ac-C6H4, 1e 5 16: 1 74 99
16 m-OMe-C6H4, 1h 5 4.5: 1 66 96
17f n-Hex, 1l 2c > 19: 1 74 91
18f (CH2)4CO2Me, 1m 2c > 19: 1 68 92
19f CH2CH2OTBS, 1n 2c > 19: 1 76 96
20f (CH2)2CH2OTBS, 1o 2c > 19: 1 73 94
21f (CH2)3CH2Cl, 1p 2c > 19: 1 60 88
22f CH2CH2Ph, 1q 2c > 19: 1 70 92
a

Conditions: 1 (2 equiv), 2 (0.16 mmol), Rh catalyst, L in PhMe at 110 °C.

b

Product selectivity (3: 4) is determined by 1H NMR of the unpurified reaction mixture.

c

Isolated yield.

d

Determined by HPLC analysis using a chiral stationary phase.

e

Absolute configuration assigned by analogy to (S)-3bc (established by X-ray analysis).

f

5 mol % Rh catalyst and 10 mol % L4 employed.

g

Isolated yield of 4 (a 2:1 mixture of imine isomers).