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. Author manuscript; available in PMC: 2018 Nov 3.
Published in final edited form as: Org Lett. 2017 Nov 3;19(21):6012–6015. doi: 10.1021/acs.orglett.7b03059

Table 2. Optimization of Sulfamate Ester Preparation.

graphic file with name nihms921397u2.jpg
entrya activating agent yield (%)b4a
1 PCl5 (2.0 equiv) 41
2 POCl3 (2.0 equiv) 44
3 SOCl2 (2.0 equiv) <5
4 (COCl)2 (10.0 equiv) ndc
5 trichlorotriazine (1.0 equiv) <5
6d DIAD, PPh3 50
7 Tf2O (1.0 equiv), Ph3PO (2.1 equiv) 56
8e Tf2O (1.5 equiv), Ph3PO (3.15 equiv) 71
9e Tf2O (1.5 equiv), Ph3PO (1.65 equiv) 78
10e, f Tf2O (1.5 equiv), Ph3PO (1.65 equiv) 95
11f, g Tf2O (1.5 equiv), Ph3PO (1.65 equiv) 94
a

General reaction conditions: 1.0 equiv n-pentanol (3a), 1.0 equiv sulfamate 2a, CH2Cl2, 2.0 equiv Et3N, Tf2O (1.5 equiv), Ph3PO (1.65 equiv), 18 h, −78 → 22°C.

b

Isolated yield.

c

Not detected.

d

No Et3N.

e

1.5 equiv triethylammonium sulfamate 2a.

f

3.0 equiv Et3N.

g

1.5 equiv trimethylammonium sulfamate 2b.