Palladium-catalyzed reactions

Palladium is probably the most versatile and exploited transition metal in catalysis due to its capability to promote a myriad of organic transformations both at laboratory and industrial scales (alkylation, arylation, cyclization, hydrogenation, oxidation, isomerization, cross-coupling, cascade, radical reactions, etc [...

Correction: A novel enantioselective synthesis of 6H-dibenzopyran derivatives by combined palladium/norbornene and cinchona alkaloid catalysis

Correction for 'A novel enantioselective synthesis of 6H-dibenzopyran derivatives by combined palladium/norbornene and cinchona alkaloid catalysis' by Di Xu et al., Org. Biomol. Chem., 2015, DOI: 10.1039/c4ob02551b

PdI2 as a simple and efficient catalyst for the hydroamination of arylacetylenes with anilines

The hydroamination reaction is a convenient alternative strategy for the formation of C– N bonds. Herein, we report a new versatile and convenient protocol for the hydroamination of arylacetylenes with anilines using palladium iodide in the absence of any added ligand as catalyst. Mild conditions, excellent regio-and stereoselectivity, and high functional group tolerance are the main features of this methodology. A subsequent reduction step gives access to a wide variety of secondary aromatic amines

Evolution of Triangular All-Metal Aromatic Complexes from Bonding Quandaries to Powerful Catalytic Platforms

This manuscript describes an overview on the literature detailing the observation of trinuclear complexes that present delocalized metal–metal bonds similar to those of regular aromatics, which are formed combining main group elements. A particular emphasis is given to the structural and electronic features of aromatic clusters that are sufficiently stable to allow their isolation. In parallel to the description of their key bonding properties, the work presents reported catalytic applications of these complexes, which already span from elaborated C–C-forming cascades to highly efficient cross-coupling methods. These examples present peculiar aspects of the unique reactivity exerted by all-metal aromatic complexes, which can often be superior to their established, popular mononuclear peers in terms of chemoselectivity and chemical robustnes

Auto-Tandem Catalysis in Ionic Liquids: Synthesis of 2-Oxazolidinones by Palladium-Catalyzed Oxidative Carbonylation of Propargylic Amines in EmimEtSO4

A convenient carbonylative approach to 2-oxazolidinone derivatives carried out using an Department of Chemistry, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy; ionic liquid (1-ethyl-3-methylimidazolium nicola.ethyl sulfate, EmimEtSO4 ) as the solvent is presented. It is based on the sequential concatenation of two catalytic cycles, both catalyzed by the same metal species (auto-tandem catalysis): the first cycle corresponds to the oxidative monoaminocarbonylation of the triple bond of Received: propargylic 16 June 2016; amines Accepted: to give 5 July 2016; the Published: corresponding date 2-ynamide intermediates, while the second one involves the cyclocarbonylation of the latter to yield 2-(2-oxooxazolidin-5-ylidene)-acetamides. Abstract: A convenient carbonylative approach to 2-oxazolidinone derivatives carried out using an Reactions areionic carried liquid out (1-ethyl-3-methylimidazolium using a simple catalytic ethyl system sulfate, EmimEtSO4) consisting as ofthe PdI solvent2 in conjunction is presented. It is with an excess of KI, and thebased catalyst/solvent on the sequential system concatenation could of two be recycled catalytic cycles, several both catalyzed times without by the same appreciable metal species loss of activity (auto-tandem catalysis): the first cycle corresponds to the oxidative monoaminocarbonylation of the after extraction of the organic product with Et2 O

Theoremata de centro gravitatis partium circuli et ellipsis

Anotaciones y firmas en portada y última páginaCopia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200

Pd-Catalysed oxidative carbonylation of α-amino amides to hydantoins under mild conditions

The first example of palladium-catalysed oxidative carbonylation of unprotected α-amino amides to hydantoins is described here. The selective synthesis of the target compounds was achieved under mild conditions (1 atm of CO), without ligands and bases. The catalytic system overrode the common reaction pathway that usually leads instead to the formation of symmetrical ureas

PENGARUH SELF ASSESSMENT SYSTEM, AKUNTABILITAS PELAYANAN PUBLIK, DAN PEMERIKSAAN PAJAK TERHADAP PENERAPAN PAJAK PERTAMBAHAN NILAI (PPN) (Survey Pada 4 Kantor Pelayanan Pajak (KPP) di Kota Bandung)

ABSTRAK Penelitian ini berjudul “Pengaruh Self Assessment System, Akuntabilitas Pelayanan Publik, dan Pemeriksaan Pajak tehadap Penerapan Pajak Pertambahan Nilai” (Survei Pada 4 Kantor Pelayanan Pajak (KPP) di Kota Bandung). Tujuan penelitian ini untuk adalah untuk mengetahui pengaruh self assessment system, akuntabilitas pelayanan publik, dan pemeriksaan pajak terhadap penerapan pajak pertambahan nilai secara parsial. Variabel pada penelitian ini adalah self assessment system, akuntabilitas pelayanan publik dan pemeriksaan pajak sebagai variabel bebas dan penerapan pajak pertambahan nilai sebagai variabel terikat. Adapun populasi dari penelitian ini adalah account representative yang terdaftar pada 4 Kantor Pelayanan Pajak di Kora Bandung yang berjumlah 50 orang account representative. Berdasarkan analisis statistik diperoleh hasil sebagai berikut: secara parsial pengaruh yang paling dominan berasal dari variabel Akuntabilitas Pelayanan Publik dengan kontribusi pengaruh sebesar 26,1%, sedangkan variabel Self Assessment System memberikan kontribusi pengaruh sebesar 17,7% dan variable Pemeriksaan Pajak memberikan pengaruh sebesar 17,6 %, sedangkan secara simultan pengaruh self assessment system, akuntabilitas pelayanan publik, dan pemeriksaan pajak berpengaruh terhadap penerapan pajak pertambahan nilai dengan kontribusi sebesar 52,5%. sedangkan sisanya yaitu sebesar 47,5% merupakan pengaruh dari variabel lain yang tidak diteliti. Kata Kunci : Pengaruh Self Assessment System, Akuntabilitas Pelayanan Publik, Pemeriksaan Pajak, Penerapan Pajak Pertambahan Nilai

Synthesis of Imidazolidin-2-ones and Imidazol-2-ones via Base-Catalyzed Intramolecular Hydroamidation of Propargylic Ureas under Ambient Conditions

The first organo-catalyzed synthesis of imidazolidin-2-ones and imidazol-2-ones via intramolecular hydroamidation of propargylic ureas is reported. The phosphazene base BEMP turned out to be the most active organo-catalyst compared with guanidine and amidine bases. Excellent chemo- and regioselectivities to five-membered cyclic ureas have been achieved under ambient conditions, with a wide substrate scope and exceptionally short reaction times (down to 1 min). A base-mediated isomerization step to an allenamide intermediate is the most feasible reaction pathway to give imidazol-2-ones, as suggested by DFT studies

Whole-brain histogram and voxel-based analyses of apparent diffusion coefficient and magnetization transfer ratio in celiac disease, epilepsy, and cerebral calcifications syndrome

BACKGROUND AND PURPOSE: Diffusion and magnetization transfer (MT) techniques have been applied to the investigation with MR of epilepsy and have revealed changes in patients with or without abnormalities on MR imaging. We hypothesized that also in the coeliac disease (CD), epilepsy and cerebral calcifications (CEC) syndrome diffusion and MT techniques could reveal brain abnormalities undetected by MR imaging and tentatively correlated to epilepsy. MATERIALS AND METHODS: Diffusion and MT weighted images were obtained in 10 patients with CEC, 8 patients with CD without epilepsy and 17 healthy volunteers. The whole brain apparent diffusion coefficient (ADC) and MT ratio (MTR) maps were analyzed with histograms and the Statistical Parametric Mapping 2 (SPM2) software. We employed the non-parametric Mann-Whitney U test to assess differences for ADC and MTR histogram metrics. Voxel by voxel comparison of the ADC and MTR maps was performed with 2 tails t-test corrected for multiple comparison. RESULTS: A significantly higher whole brain ADC value as compared to healthy controls was observed in CEC (P = 0.006) and CD (P = 0.01) patients. SPM2 showed bilateral areas of significantly decreased MTR in the parietal and temporal subcortical white matter (WM) in the CEC patients. CONCLUSION: Our study indicates that diffusion and MT techniques are also capable of revealing abnormalities undetected by MR imaging. In particular patients with CEC syndrome show an increase of the whole brain ADC histogram which is more pronounced than in patients with gluten intolerance. IN CEC patients, voxel-based analysis demonstrates a localized decrease of the MTR in the parieto-temporal subcortical WM