A novel SBA-15 supported catalyst PdL(n)@SBA-15 containing a 2-pyridyl-1,2,3-triazole ligand framework was prepared via a "click" route, in which the click-triazole acted as both a stable linker and a good chelator. The catalyst was characterized and applied for the aerobic oxidation of alcohols, and the product was obtained in up to 98% yield.

A water-soluble palladium complex (PdL n @β-CD) was designed and prepared based on functionalized β-cyclodextrin. It showed high turnover numbers (TONs) and turnover frequencies (TOFs) of up to 9.9 × 10 8 and 4.9 × 10 8 h −1 , respectively, in aqueous Suzuki-Miyaura coupling reactions. The detailed reason for the excellent catalytic activity was studied. Scheme 1 Synthesis of PdL n @β-CD. Reaction conditions: (a) TsCl, NaOH, H 2 O, 0-5 °C, 4 h, 24.3%; (b) NaN 3 , DMF, 75 °C, 4 h, 93.6%; (c) 2-ethynylpyridine, CuSO 4 /sodium ascorbate, DMSO-H 2 O, r.t., 1 d, 92.1%; (d) Pd(OAc) 2 , toluene, r.t., 12 h. † Electronic supplementary information (ESI) available: Detailed synthetic procedure of PdL n @β-CD and characterization date of the products. See

A novel and highly practical copper-catalyzed aerobic alcohol oxidation system with L-proline as the ligand at room temperature has been developed. A wide range of primary and secondary benzylic alcohols tested have been smoothly transformed into corresponding aldehydes and ketones with high yields and selectivities.

Using in situ generated H 2 O 2 is potentially an effective approach for benzyl alcohol selective oxidation. While the microporous titanium silicate (TS-1) supported with Pd is promising for selective oxidation, the Pd particles are preferentially anchored on the external surface, which leads to the problems such as non-uniform dispersion and low thermal stability. Here, we prepared a Pd@HTS-1 catalyst in which the Pd subnanoparticles were encapsulated in the channels of the hierarchical TS-1 (HTS-1), for benzyl alcohol selective oxidation with in situ produced H 2 O 2 . We find that the oxidation rate of benzyl alcohol by in situ H 2 O 2 over the Pd@HTS-1 is up to 4268.8 mmol h –1 kg cat –1 , and the selectivity of benzaldehyde approaches 100%. In contrast to the conventional Pd/HTS-1, the present Pd@HTS-1 benefits the benzyl alcohol selective oxidation due to the increased dispersion of Pd particles (forming uniformly dispersed subnano-sized particles), as well as the confinement effect and hierarchical porosity of the HTS-1 host. We further suggested that hydrogen peroxide produced in situ from the molecular hydrogen and oxygen over the Pd sites can be spilled over to the framework Ti 4+ sites, forming the Ti-OOH active species, which selectively oxidizes the chemisorbed benzyl alcohol to benzaldehyde on the Pd sites.

An efficient catalytic system for Suzuki–Miyaura coupling reactions in neat water has been developed by using a water‐soluble Pd(l‐proline)2 catalyst. Under the optimized conditions, various biaryl compounds were obtained in good to excellent yields and a wide range of functional groups on the tested substrates were well tolerated. The catalytic system could be reused at least six times with no significant loss in its activity. Copyright © 2014 John Wiley & Sons, Ltd.