Naphthyl, bridging ligand

The best enantioselectivity (35% ee) was observed in the reaction of l-(l-naphthyl)-2-propyn-l-ol with acetone in the presence of a complex bearing a 1-naphthylethylthio-lato moiety as a chiral ligand. Although the enantioselectivity is not yet satisfactory, this was the first example of an enantioselective propargylic substitution reaction catalyzed by transition metal complexes [27]. It is noteworthy that the chiral thiolate-bridged ligands work to control the chiral environment around the diruthenium site. 

The first cylindrical macrotricyclic ligands synthesized were (52a) and SSa-d).58 70 Cryptands in which the two monocycles are even farther apart as a result of bridging naphthyl, biphenyl and. related groups have also been reported.188,1 9 The smaller macrocycle (52a) forms complexes with a variety of metal cations, including two silver(I) ions.69,70 190 Crystal data results for the latter complex indicate both Ag+ ions are located slightly out of the plane of the macrocycles (undoubtedly the result of macrocyclic size constraints), but within the central main cavity, with an Ag—Ag distance of 3.88 A.191... 

A strategy for stereoblock propylene polymerization that can be viewed as a hybrid between those described in Sections 8.3.2 and 8.3.3 consists of using metallocene catalysts with hapto-fiexible cyclopentadienyl-aryl ligands.The catalyst precursors in these systems are Ti(IV) or Zr(IV) complexes bearing a (substituted) cyclopentadienyl or indenyl ligand bridged to a neutral aromatic moiety such as a (substituted) phenyl or naphthyl. A typical example is 4 (Scheme 8.5), which... 

Abstract. The synthesis of 1,2- and l,3-calix[4]-Z w-crowns, double calix[4]arenes and double calixcrowns have been shown to depend on the reaction conditions (nature of the base, structure of the ditosylates, and the stoichiometry of the reactants). The 1,3-altemate conformation of the 1,3-calix[4]- w-crowns was shown to be favourable to the selective complexation of cesium cation. The observed Na /Cs selectivity was exploited in separation processes using them as carriers in transport through supported liquid membranes (SLMs). The best Na "/Cs selectivity (1/45 000) was observed for the naphthyl derivative 7. Calix(aza)crowns and 1,3-calix[4]-/ w-(aza)-crowns were also produced through the preliminary formation of the Schiff base-calixarenes, which were further hydrogenated. The syntheses consisted of the 1,3-selective alkylation of calixarenes followed by cyclization into a 1,3-bridged calixarene or by the direct 1,3-capping of the calixarene with appropriate ditosylates. Soft metal complexation by these ligands is also presented. 

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