Suzuki-type coupling reactions can be performed directly in air using a catalytic system composed of iodine, potassium carbonate, and polyethylene glycol 400 (I 2 /K 2 CO 3 /PEG-400). Iodine was found to be an effective additive for accelerating these couplings. The methodology is also suitable for the coupling of (E)-b-bromostyene with phenylboronic acid, with retention of the double bond geometry.

Iodine is able to catalyze the homocoupling of arylboronic acids in moderate to good yields in PEG‐400 under aerobic conditions. This transition‐metal‐free catalytic system is readily available at low cost, which is practical and useful. It is noteworthy that a high activity of our catalytic system could be maintained under mild conditions (100 °C) by addition of water.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Highly effective coupling of imidazoles with (E)‐vinyl halides can be achieved by using readily available iron catalysts under ligand‐free, copper‐free and palladium‐free conditions. Coupling of (E)‐vinyl bromides led to (Z)‐products predominantly, while the reactions of (E)‐vinyl chlorides afforded (E)‐isomers as the major products.

An efficient and straightforward copper-catalyzed method allowing vinylation of N-nucleophiles with various substituted (E)-vinyl bromides under palladium-free and ligand-free conditions has taken a high yield (up to 95%). Noteworthy is that the doublebond geometry of these vinyl halides was retained with our protocol.

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