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The iridium-catalyzed C-H borylation of diethyl phenylphosphonate results in nonselective mono and bisborylation to afford a near statistical mixture of 3-, 3,5- and 4-boryl substituted aryl phosphonates whereas 3-substituted aryl phosphonates undergo highly regioselective C-H borylation to afford the corresponding meta-phosphonate substituted arylboronic esters as the sole product; the resulting boronic esters were used as nucleophilic reagents in a subsequent palladium-catalyzed Suzuki–Miyaura cross-coupling to generate a range of biarylmonophosphonates. Gratifyingly, the Suzuki–Miyaura cross-coupling can be conducted without purifying the boronic ester which greatly simplifies the synthetic procedure. [ABSTRACT FROM AUTHOR]

Abstract: Palladium nanoparticles stabilized by heteroatom donor‐modified polystyrene‐based polymer immobilized ionic liquids (PdNP@HAD‐PIILP; HAD‐PPh2, OMe, NH2, CN, pyrrolidone) are highly efficient catalysts for the Suzuki‐Miyaura cross‐coupling in aqueous media under mild conditions. Catalyst modified with phosphine was consistently the most efficient as it gave high yields across a range of substrates under mild conditions at low catalyst loadings. Incorporation of polyethylene glycol into the phosphine modified immobilised ionic liquid support improved catalyst efficacy by improving dispersibility and facilitating access to the active site. Moreover, each of the heteroatom modified catalysts was more active than the corresponding unsubstituted imidazolium‐based polystyrene benchmark as well as commercial samples of Pd/C. Catalyst generated in situ from either [PdCl4]@PPh2‐PIILP or its PEGylated counterpart [PdCl4]@PPh2‐PEGPIILP, by reduction with phenylboronic acid, outperformed their pre‐formed counterparts for the vast majority of substrates examined. The turnover frequency of 16,300 h−1 obtained at room temperature is one of the highest to be reported for palladium nanoparticle‐catalysed Suzuki‐Miyaura cross‐coupling between 4‐bromoacetophenone and phenylboronic acid in aqueous media under such mild conditions. [ABSTRACT FROM AUTHOR]

Abstract: Glycine-derived N-tosyl-5,5-divinyloxazolidin-2-one 10 undergoes a palladium catalysed decarboxylative ring-opening cyclization with strongly electron deficient alkylidenemalonate derivatives to give highly substituted pyrrolidines 14 containing two contiguous quaternary centres. [Copyright &y& Elsevier]

[Display omitted] • Pd NPs supported ordered mesoporous were synthesized. • Pd NPs were characterized by XPS, XRD, TEM, SEM, FT-IR and NMR spectroscopy. • Catalyst loading, temperature, NaOH and NaBH 4 concentration effects were examined. • Pd NPs catalyze the hydrolytic production of H 2 from NaBH 4 with TOF of 176 mole H2.mol cat −1.min−1. • Pd NPs catalyst retains 71.6% of its initial catalytic activity after five cycles. The ordered mesoporous silica supported Pd NPs, denoted as Pd NPs@[KIT-6] 2 and Pd NPs@[KIT-6]-PEG-imid 6 , were synthesized by a deposition precipitation method using the [KIT-6] 1 or [KIT-6]-PEG-imid 5 , respectively, and Na 2 PdCl 4 followed by in situ reduction by NaBH 4. The obtained supported Pd NPs 2 and 6 were fully characterized by XPS, XRD, TEM, SEM, FT-IR and solid-state 29Si and 13C NMR spectroscopy. The effect of several parameters such as catalyst loading, temperature, NaOH and NaBH 4 concentration were examined to obtain the optimum reaction conditions. The supported Pd NPs 2 and 6 catalyze the hydrolytic production of H 2 from NaBH 4 with notable efficiencies and the catalyst stabilized by PEG and imidazolium ionic liquid based-[KIT-6] 6 is more active than its [KIT-6] counterpart 2. A TOF of 176 mole H2.mol cat −1.min−1 for 6 was achieved when the reaction was performed with a low catalyst loading of 0.1 mol%. Reaction kinetics studies showed that the hydrolysis is first order in catalyst and NaBH 4 with apparent E a of 35.0 and 35.7 kJ mol−1 for 2 and 6 , respectively. The efficiency of catalyst 6 for the hydrolysis of NaBH 4 was investigated in H 2 O and D 2 O and indicated that the reaction is considerably faster in H 2 O than in D 2 O with primary KIE k H /k D = 2.36. In addition, the PdNPs based [KIT-6] mesoporous silica 6 retains 71.6% of its initial efficiency after five cycles. [ABSTRACT FROM AUTHOR]