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The 16th International Symposium on Organometallic Chemistry Directed Towards Organic Synthesis (OMCOS 16) was held in Shanghai, China during the period of 24-28 July 2011. It was jointly organized by the Shanghai Institute of Organic Chemistry (SIOC), the Chinese Academy of Sciences (CAS), and East China Normal University under the auspices of the International Union of Pure and Applied Chemistry. It was held at the Shanghai International Convention Center, located in the heart of the Lujiazui-Shanghai Financial and Trade zone, adjacent to the Oriental Pearl TV Tower and facing the multinational styles of architecture along the Bund across the Huangpu River, nicely showing part of the history and the dynamic nature of China at this moment. It was the first time for mainland China to host the OMCOS meeting following the successful series of symposia held at Fort Collins (1981), Dijon (1983), Kyoto (1985), Vancouver (1987), Florence (1989), Utrecht (1991), Kobe (1993), Santa Barbara (1995), Gottingen (1997), Versailles (1999), Taipei (2001), Toronto (2003), Geneva (2005), Nara (2007), and Glasgow (2009). The symposium program featured 11 plenary lectures, 13 invited lectures, 12 oral presentations, one OMCOS Award Lecture (sponsored by Springer Verlag and the Yen-Chuang Foundation), and one OBC Award Lecture (sponsored by the Royal Society of Chemistry). Notably, the plenary lecture given by the Nobel laureate, Prof. Ei-ichi Negishi, was delivered right after the reception dinner on 24 July. Prof. Frank Glorius from Universität Münster received the OMCOS Award, and Prof. Michael C. Willis from the University of Oxford received the OBC Award. The symposium was attended by 993 participants from 21 countries and areas. The scientific program also presented well-supported poster sessions comprising 507 posters of remarkably high quality. On the basis of assessment by the distinguished international committee, 20 posters were awarded with the OMCOS-16 Poster Prizes, sponsored by Henkel, John Wiley, IUPAC, Thieme, the Royal Society of Chemistry, and Elsevier. This issue of Pure and Applied Chemistry comprises a collection of 9 papers based upon lectures delivered at OMCOS-16 (Conference Editor, Shuli You), offering the readers a glimpse of the fascinating achievements in this area communicated at the symposium. The series will continue with OMCOS-17, which will be held in Fort Collins, Colorado, USA (www.omcos17.com), 28 July-1 August 2013, under the chairmanship of Prof. Tomislav Rovis. Shengming Ma and Kuiling Ding Conference Chairs

The combined use of asymmetric Au(I) catalysis with allylic as well as propargylic alcohols proved to be a competent synthetic tool, toward the realization of complex molecular organic architectures in a stereochemically defined manner. In particular, allylic alcohols have been utilized as alkylating agents in the synthesis of tetrahydrocarbazoles/carbolines and morpholines by means of new C–C and C–X bond-forming processes. Analogously, the direct activation of indole-propargylic alcohols with cationic Au complexes opened a direct access to tetracyclic fused indolines in a highly stereoselective manner.

Iron-catalyzed reactions are receiving a surge of interest owing to the natural abundance and biocompatibility of Fe and the urge to develop practically useful sustainable catalysis for fine chemical industries. This article is a brief account of our studies on the C–O and C–N bond formation reactions catalyzed by Fe complexes supported by oligopyridine, macrocyclic tetraaza, and fluorinated porphyrin ligands. The working principle is the in situ generation of reactive Fe=O and Fe=NR intermediates supported by these oxidatively robust N-donor ligands for oxygen atom/nitrogen group transfer and insertion reactions. The catalytic reactions include C–H bond oxidation of saturated hydrocarbons (up to 87 % yield), epoxidation of alkenes (up to 96 % yield), cis -dihydroxylation of alkenes (up to 99 % yield), epoxidation–isomerization (E–I) reaction of aryl alkenes (up to 94 % yield), amination of C–H bonds (up to 95 % yield), aziridination of alkenes (up to 95 % yield), sulfimidation of sulfides (up to 96 % yield), and amide formation from aldehydes (up to 89 % yield). Many of these catalytic reactions feature high regio- and diastereoselectivity and/or high product yields and substrate conversions, and recyclability of the catalyst, demonstrating the applicability of Fe-catalyzed oxidative organic transformation reactions in practical organic synthesis.

N -Heterocyclic carbene (NHC) copper complexes serve as an excellent catalytic system for carboxylation of alkyl-, aryl-, and alkenylboron compounds and some aromatic heterocyclic C-H bonds with carbon dioxide (CO 2 ), to afford various functional-group-containing carboxylic acids or their ester derivatives. Some key reaction intermediates have been isolated and structurally characterized, thus providing important insight into the mechanistic details of these catalytic reactions.

Studies aimed at synthesizing surfactants from biomass-based feedstocks using Pd-catalyzed telomerization of 1,3-butadiene resulted in the development of a highly active catalyst system. A ligand screening was performed, and Pd/tris(2-methoxyphenyl)phosphine (TOMPP) was identified as the most promising catalyst. A solvent- and base-free protocol was developed, which allows efficient and selective conversion of a wide variety of polyol substrates (e.g., glycerol, diols, carbohydrates, and sugar alcohols). In the case of hemi-acetal bearing sugars, catalyst deactivation was observed and mechanistic studies showed that extensive formation of ligand-derived phosphonium species depleted the amount of available ligand. Stoichiometric coordination reactions gave insight into the phosphine alkylation mechanism and demonstrated the reversibility of the observed reaction. A simple and efficient one-pot synthesis method was developed for the preparation of [Pd((1-3,7,8η)-( E )-octa-2,7-dien-1-yl)(PR 3 )] + complexes, which are key reactive intermediates. Based on these studies, an extended telomerization mechanism is proposed, which accounts for the formation of ligand-derived phosphonium species and the reversibility of reaction pathways.

Ruthenium-catalyzed transfer hydrogenation of diverse π-unsaturated reactants in the presence of aldehydes provides products of carbonyl addition. Dehydrogenation of primary alcohols in the presence of the same π-unsaturated reactants provides identical products of carbonyl addition. In this way, carbonyl addition is achieved from the alcohol or aldehyde oxidation level in the absence of stoichiometric organometallic reagents or metallic reductants. In this account, the discovery of ruthenium-catalyzed C–C bond-forming transfer hydrogenations and the recent development of diastereo- and enantioselective variants are discussed.

Very high asymmetric inductions result in the Pd-catalyzed intramolecular arylation of amides to give 3,3-disubstituted oxindoles when new in situ-generated chiral N -heterocyclic carbene (NHC*) ligands are employed. Structural studies show that conformational locking to minimize allylic strain is the key to understanding the function of these ligands. New applications of these ligands in the frontier area of asymmetric coupling reactions involving C(sp 3 )–H bonds are detailed. Highly enantioenriched fused indolines are accessible using either preformed- or in situ-generated Pd-NHC* catalysts. Remarkably, this occurs at high temperature (140–160 °C) via excellent asymmetric recognition of an enantiotopic C–H bond in an unactivated methylene unit.

We report recent progress on Au- and Pt-catalyzed cascade reactions to access complicated molecular frameworks. Reported reactions include new cyclization/cycloaddition cascades on carbonyl and epoxide substrates tethered with an allene, alkene, and alkyne. Such substrates enable Au-catalyzed cascade reactions comprising an initial cyclization to form reactive 1, n -dipole that undergoes subsequent cycloadditions with suitable dipolarophiles.

Single-handed PQXphos, i.e., helical poly(quinoxaline-2,3-diyl)s bearing diarylphosphino pendant groups, served as remarkable chiral ligands in palladium-catalyzed asymmetric hydrosilylation of styrenes and asymmetric biaryl synthesis by Suzuki–Miyaura coupling, affording up to 98 % enantiomeric excess (e.e.) in both reactions. A palladium complex of high-molecular-weight variant (1000mer) of PQXphos could be reused eight times by virtue of the formation of an insoluble polymer complex. PQXphos underwent solvent-dependent inversion of the helical sense, enabling production of either of two enantiomeric products using a single PQXphos.

Molecular transformations using Au, Pd, and Cu nanoporous skeleton catalysts and the reactivity difference between those catalysts and the corresponding well-known homogeneous molecular catalysts are described. Nanoporous skeleton catalysts (e.g., PdNPore) can be fabricated through dealloying of the corresponding Pd-containing alloy Pd x M 1 y M 2 z .

Recommendations are given for reporting in the primary scientific literature of measurements involving phase equilibrium. The focus is on documentation issues, and many of the recommendations may also be applied to the more general fields of thermodynamic and transport properties. The historical context of the work and specific plans for implementation of the recommendations are discussed.

Procedures for the characterization of photoluminescence measuring systems are discussed, focusing on spectrofluorometers and fit-for-purpose methods including suitable standards. The aim here is to increase the awareness for the importance of a reliable instrument characterization and to improve the reliability and comparability of measurements of photoluminescence.