Scheme 5.
Reagents and conditions: (i) 8, CuSO4 (5 mol %), sodium ascorbate (10 mol %), MeOH/H2O (3:1); (ii) 7 or 11 or 14, CuBr (5 mol %), sodium ascorbate (10 mol %), TBTA (5 mol %), MeOH/H2O/MeCN (1:1:1), r.t., sonication.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.