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. Author manuscript; available in PMC: 2019 Dec 21.
Published in final edited form as: Adv Synth Catal. 2018 Sep 30;360(24):4705–4709. doi: 10.1002/adsc.201800876

Table 1.

Optimization of the cyanomethylation of 2,2,2-trifluoroacetophenone.[a]

graphic file with name nihms-1020169-t0007.jpg

Entry Base (mol%) Solvent Time (h) Temp (°C) Yield (%)[b]
1 DBU (50) THF 42 25 49
2 Et3N (50) THF 42 25 45
3 DIPEA (50) THF 42 25 29
4 DABCO (50) THF 42 25 13
5 TMEDA (50) THF 42 25 23
6 DMAP (50) THF 42 25 36
7 Barton’s base (50) THF 42 25 42
8 K2CO3 (50) THF 42 25 <5
9 Cs2CO3 (50) THF 42 25 9
10 None THF 42 25 nr
11 Et3N (50) CH2Cl2 48 25 <5
12 Et3N (50) 1,4-dioxane 48 25 27
13 Et3N (50) toluene 48 25 <5
14 Et3N (50) CH3CN 48 25 8
15 Et3N (50) CH3OH 48 25 <5
16 Et3N (50) H2O 48 25 nr
17 Et3N (10) neat, MW 0.75 100 89
18 Et3N (50) THF 16 60 99
19 Et3N (20) THF 21 60 98[d]
20[c] Et3N (20) THF 24 60 98[d]
21[c] Et3N (10) THF 36 60 91
[a]

Conditions: 0.3 mmol of 1a, 0.9 mmol of 2, 1 mL of solvent.

[b]

By NMR analysis.

[c]

Two equivalents of 2 were used. The reaction is slow and takes 3 days with 1.5 equivalents of 2.

[d]

Isolated yields.