Table 2.

Optimization of reaction conditions for the transformation of enones.

entry	conditions	equiv of azide/equiv of Lewis acid	reaction time	yield (%)a
1b	HN3, BF3·OEt2, benzene, rt	16:5	72 h	52
2	TMSN3, TMSOTf, DCM, rt	6:3	72 h	69
3	TMSN3, TMSOTf, DCM, rt	12:6	48 h	64
4	TMSN3, TMSOTf, ACN, rt	6:3	4 h	42
5	TMSN3, BF3·OEt2, DCM, rt	6:3	72 h	66
6	TMSN3, BF3·OEt2, DCM, rt	12:6	72 h	68
7	TMSN3, BF3·OEt2, ACN, rt	6:3	48 h	51
8	TMSN3, BF3·OEt2, ACN, rt	12:6	48 h	51
9c	TMSN3, BF3·OEt2, TMSOTf, ACN, rt	6:3	4 h	40
10c	TMSN3, BF3·OEt2, TMSOTf, ACN, 0–5 °C	6:3	4 h	42
11c	TMSN3, BF3·OEt2, TMSOTf, DCM, rt	12:6	24 h	42

^aIsolated yield. ^bConcentration of hydrazoic acid solution obtained by the literature protocol that we used is between 6 and 10% [36]. ^cEquimolar amounts of Lewis acids were added to the reaction mixture in sequence.