Table 1. Reaction Optimization for the Hydroamination Reaction between Alkynes and N,N-Dialkylhydroxylamines^a.

					yield (%)b
entry	solvent	temp. (°C)	time (h)	conv. (%)	4	5 + 5′
1	CHCl3	50	6	65	5	50
2	CHCl3	60	6	84	23	48
3	CHCl3	70	6	100	49	31
4	CH2Cl2	60	6	100	46	43
5	DCE	60	6	89	45	20
6	iPrOH	60	6	59	3	47
7	TFE	60	6	49	2	47
8	iPrOH	60	12	77	26	51
9	TFE	60	12	81	4	76
10	50% TFE/CHCl3	60	6	55	<1	52
11	20% TFE/CHCl3	60	6	62	<1	61
12c	20% TFE/CHCl3	60	6	33	<1	28
13d	20% TFE/CHCl3	60	6	35	<1	26
14	20% TFE/CHCl3	60	18	95	<1	96

^aConditions: alkyne 3 (0.2 mmol, 1 equiv, 0.2 M), N,N-diethylhydroxylamine (1 mmol, 5.0 equiv, 1 M).

^bYields were determined by NMR using benzotrifluoride as an internal standard.

^cN,N-Diethylhydroxylamine (2 equiv) was used.

^dConcentration of 0.1 M. Temp. = temperature; conv. = conversion.