Abstract The cross-coupling reaction between diethyl ethynylphosphonate (1) and several aromatic iodides under the Sonogashira conditions (Cl2Pd (PPh3) 2/CuI/Et3N) gives only minute amounts of the expected 1-alkynylphosphonates. Yields of about 20% are achieved upon using Pd (OAc) 2/2PPh3/Et3N in place of the previous catalytic system. Side-reactions involving 1 and the mine are shown to be responsible for these low yields. Metalation of 1 ...
