A new tropos ligand with an integrated anion receptor site has been prepared. Chiral carboxylate and phosphate anions that bind in the anion receptor unit proved capable of stabilizing chiral conformations of the achiral flexible bidentate biaryl phosphite ligand, as shown by variable temperature 1 H and 31 P NMR spectroscopical studies of palladium(0) olefin complexes. Palladium allyl complexes of the supramolecular ligand-chiral cofactor assemblies catalyzed asymmetric allylic substitutions of rac-(E)-1,3-diphenyl-2propenyl carbonate and rac-3-cyclohexenyl carbonate with malonate and benzylamine as nucleophiles to provide nonracemic products. Although moderate enantioselectivities were observed, (ee:s up to 66%), the results confirm the ability of the anionic guests to affect the conformation of the ligand.

A diastereoselective metal-catalyzed reaction of 2-(2-enynyl)pyridines and cyclic enamines is reported. The method provides access to a variety of substituted indolizine derivatives by variation of the enyne component and the reaction conditions. Performing the reaction using a preformed enamine led to the formation of polycyclic indolizines. With in situ generated enamines, ketone-containing indolizine derivatives were obtained. An asymmetric reaction of 2-(2-enynyl)pyridines and enamines generated from an aldehyde and a catalytic amount of amine is presented.

A highly efficient N-trifluoromethylation of nitrosoarenes is reported. The inexpensive and convenient Langlois reagent (sodium triflinate) is employed as a CF-radical source in combination with a copper catalyst and an oxidant. N-Trifluoromethylated hydroxylamines are obtained in high yields within 1 h at room temperature. The addition of hydroquinone was found to be instrumental to prevent the formation of side products. The method is high-yielding, is scalable, and displays a high functional group tolerance.

A diastereoselective three-component reaction between alkynyl enones, aldehydes and secondary amines is reported. With the aid of a benign indium catalyst, a range of highly substituted cyclopenta [c]furan derivatives can be obtained in a single-step procedure. The formation of the stereodefined heterocyclic motifs takes place via in situ generation of enamines followed by two sequential cyclization steps.Multicomponent reactions (MCRs) involving sequential cyclization steps are powerful approaches for the construction of structurally diverse scaffolds of chemical and biological interest.[1] The selective formation of multiple bonds in a single operational step offers a challenge as well as a great potential for improving atom economy, step efficiency and sustainability in synthesis. Ideally, multicomponent reactions do not only allow for modulative syntheses of compounds with divergent substitution patterns, but may also provide a platform for further transformations.An example of valuable heterocyclic motifs where MCR approaches have been utilized is furan derivatives.[2] These motifs are important in organic synthesis due to their presence as key structural scaffolds in certain natural products and pharmaceuticals, [3] and also as useful building blocks for synthesis. [4] Transition metal catalysis has been widely used as a tool for the synthesis of functionalized furan derivatives.[5] The use of gold catalysis for the cyclization of 2-(1-alkynyl)-2-alken-1-ones was first reported by Larock [6] in 2004 and has since been further developed by Zhang [7] and others. [8] For example, the Au I -catalyzed intermolecular reactions of alkynyl enones with nitrones, [7d,l] 3-styrylindoles, [7h] and N-allenamides [7n] provide access to highly functionalized furans (Scheme 1 a-c).Despite the success of transition metal catalysis for the assembly of valuable heterocycles via p-Lewis acid activation, the use of p-block elements can offer new synthetic possibilities. As previously demonstrated, indium reagents and catalysts generally display a high functional group tolerance, providing a useful tool for novel transformations.[9] Herein, a catalytic MCR of alkynyl enones 1, aldehydes and secondary amines is reported (Scheme 1 d).In order to develop an efficient catalytic system, and to avoid the formation of hydroamination and aza-Michael sideproducts, a catalyst screening using alkynyl enone 1 a, hydrocinnamaldehyde (2 a), and diisopropylamine (3 a) was performed (Table 1). In analogy with literature reports, we investigated PPh 3 AuCl as a catalyst in the presence of molecular sieves in 1,2-dichloroethane (