Table 2.

Optimization of the elimination protocol and formation of vinyl azide 4a under batch conditions (entries 1–7) and as a flow protocol (entry 8).

entry	base	solvent	T [°C]	t [h]	yielda
1	1.5 equiv KOt-Bu	Et2O	rt	2	95%
2	1.5 equiv KOt-Bu	CH2Cl2	rt	2	decomposition
3	5 equiv K2CO3	CH2Cl2	rt	18	5%
4b	5 equiv K2CO3	CH2Cl2	60	18	23%
5	2.5 equiv DIPEAc	DMF	60	2	92%
6	2 equiv DBU	CH2Cl2	rt	1.5	92%
7	2 equiv PS–DBUd	CH2Cl2	rt	1.5	93%
8e	2 equiv PS–DBU	CH2Cl2	rt	0.04 mL/min	complete transformation

^aIsolated yields; ^bReaction was carried out in a microwave-compatible tube heated in an oil bath, ^cDIPEA = diisopropylethyl amine; ^dPS–DBU = polystyrene-bound 1,8-diaza-[5.4.0]bicyclo-7-undecene (8); ^eFlow process: Glass reactor (12 cm length and 8.5 mm internal diameter) filled with polymer 8 (0.5 g; theoretical loading = 1.15 mmol/g).