1: 99 percent / N-Bu3SnH / diethyl ether / 10 h / Heating 2: 74 percent / p-TsOH / methanol / 0.67 h / Ambient temperature 3: 71 percent / (PhO)2P(O)N3,Ph3P, (NCO2Et)2 / tetrahydrofuran / 0.17 h / Ambient temperature 4: 43 percent / n-Bu3SnH / benzene / 1.5 h / Heating View Scheme