Categories: C-Br Bond Formation >
Synthesis of alkynyl bromides
The use of chloramine-B as the oxidant and KI or NaBr as the halogen source enables a direct oxidative halogenation of terminal alkynes to provide synthetically valuable 1-iodoalkynes and 1-bromoalkynes in very good yields under mild reaction conditions.
X. Liu, G. Chen, C. Li, P. Liu, Synlett, 2018, 29, 2051-2055.
Using triethylamine as catalyst in Hunsdiecker reactions with N-halosuccinimides as Br+ or I+ source, cinnamic acids, and propiolic acids are converted to the corresponding α-halostyrenes and 1-halo-1-alkynes in good isolated yields within 1-5 min.
J. Prakash, S. Roy, J. Org. Chem., 2002, 67, 7861-7864.
Organotrifluoroborates are rapidly and regioselectively converted into organic bromides in excellent yields under mild conditions, using sodium bromide in the presence of chloramine-T.
G. W. Kabalka, A. R. Mereddy, Organometallics, 2004, 23, 4519-4521.