6.4. Polyynes 3123 6.5. Using R-Hydroxy Stannanes 3124 6.6. Using the Hurtley Reaction 3124 6.7. Using a Methylenation Reaction 3125 7. Conclusions and Future Prospects 3125 8. Uncommon Abbreviations 3125 9. Acknowledgments 3125 10. Note Added in Proof 3125 11. References 3126 * Authorstowhomcorrespondenceshouldbeaddressed(evano@chimie.uvsq.fr, nicolas.blanchard@uha.fr). † Université de Versailles Saint Quentin en Yvelines. ‡ Université de Haute-Alsace. Chem. Rev. 2008, 108, 3054–3131 3054

Copper-mediated coupling reactions and their applications in natural products and designed biomolecules synthesis.

Copper-catalyzed Ullmann condensations are key reactions for the formation of carbon-heteroatom and carbon-carbon bonds in organic synthesis. These reactions can lead to structural moieties that are prevalent in building blocks of active molecules in the life sciences and in many material precursors. An increasing number of publications have appeared concerning Ullmann-type intermolecular reactions for the coupling of aryl and vinyl halides with N, O, and C nucleophiles, and this Minireview highlights recent and major developments in this topic since 2004.

Catalytic C-C, C-N, and C-O Ullmann-type coupling reactions.

Iron Catalysis in Organic Synthesis

For green and sustainable chemistry, molecular oxygen is considered as an ideal oxidant due to its natural, inexpensive, and environmentally friendly characteristics, and therefore offers attractive academic and industrial prospects. This critical review introduces the recent advances over the past 5 years in transition-metal catalyzed reactions using molecular oxygen as the oxidant. This review highlights the scope and limitations, as well as the mechanisms of these oxidation reactions (184 references).

Recent advances in transition-metal catalyzed reactions using molecular oxygen as the oxidant

The abundance of the biaryl structural motif in natural products, in biologically active molecules and in materials chemistry has positioned aryl–aryl (Ar–Ar) bond formation high on the agenda of synthetic chemists. For decades well-known reactions such as the Mizoroki–Heck and Suzuki–Miyaura have been the methods of choice to furnish biaryls. More recently, however, alternative methods, most notably direct arylation via C–H activation, have become the focus of many research groups. Compared to traditional methods, direct arylation affords Ar–Ar compounds in fewer steps by removing the need for prefunctionalisation. Furthermore, given that either one or two hydrogens are targeted, less waste and good atom economy are features of this methodology. This critical review covers, in the main part, reports from January 1, 2006, to October 22, 2008 (117 references).

Recent advances in aryl–aryl bond formation by direct arylation

Yttrium(III) nitrate hexahydrate [Y(NO3)3.6H2O] as a catalyst for organic reaction is described for the first time. The catalytic activity is demonstrated using Biginelli reaction as a model under solvent-free conditions. Excellent yields of dihydropyrmidinones are obtained at 70 °C within a short reaction time (10–50 min) and the catalyst is also recyclable. Other advantages over the classical method include greater substrate compatibility, faster reaction rates and easy workup procedures.

Malhari D. Bhor

Papers

Y(NO3)3·6H2O: A novel and reusable catalyst for one pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions

Palladium bis(2,2,6,6-tetramethyl-3,5-heptanedionate): an efficient catalyst for regioselective C-2 arylation of heterocycles

Direct reductive amination of carbonyl compounds with primary/secondary amines using recyclable water-soluble FeII/EDTA complex as catalyst

N-Arylation of aliphatic, aromatic and heteroaromatic amines catalyzed by copper bis(2,2,6,6-tetramethyl-3,5-heptanedionate)

Y(NO3)3·6H2O catalyzed regioselective ring opening of epoxides with aliphatic, aromatic, and heteroaromatic amines