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991.
Stefano TartaggiaPierluigi Padovan Giuseppe BorsatoOttorino De Lucchi Fabrizio Fabris 《Tetrahedron letters》2011,52(34):4478-4480
Enantiopure (−)-5-oxoborneol was obtained in 35% overall yield in two steps, starting from readily available (−)-bornyl acetate and using oxone® as a safe and inexpensive oxidant. The reported procedure avoids the use of large excess of noxious chromium(VI), which was required by the so far reported syntheses. 相似文献
992.
Elisabetta Schievano Ileana Menegazzo Ester Marotta Stefano Mammi 《Magnetic resonance in chemistry : MRC》2011,49(8):523-528
The chemistry of dyes and pigments is relevant to the textile industry, because of the importance to establish the best conditions for the finishing process and to understand the interactions among various compounds to yield the correct hue and nuances. For this reason, the molecular structure of a monoazo acid dye, C.I. Acid Red 131, was elucidated and characterized by homo‐ and hetero‐nuclear NMR, MS, IR and UV spectroscopy techniques. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
993.
Dr. Allegra Franchino Àlex Martí Dr. Stefano Nejrotti Prof. Antonio M. Echavarren 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(46):11989-11996
A library of gold(I) chloride complexes with phosphine ligands incorporating pendant (thio)urea and squaramide H-bond donors was prepared with the aim of promoting chloride abstraction from Au(I) via H-bonding. In the absence of silver additives, complexes bearing squaramides and trifluoromethylated aromatic ureas displayed good catalytic activity in the cyclization of N-propargyl benzamides, as well as in a 1,6-enyne cycloisomerization, a tandem cyclization-indole addition reaction and the hydrohydrazination of phenylacetylene. Kinetic studies and DFT calculations indicate that the energetic span of the reaction is accounted by both the chloride abstraction step, facilitated by the bidentate H-bond donor via an associative mechanism, and the subsequent cyclization step. 相似文献
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Divergent Solid‐Phase Synthesis of Natural Product‐Inspired Bipartite Cyclodepsipeptides: Total Synthesis of Seragamide A 下载免费PDF全文
Prof. Dr. Hans‐Dieter Arndt Dr. Stefano Rizzo M. Sc. Christina Nöcker Dr. Vijay N. Wakchaure Dr. Lech‐Gustav Milroy B. Sc. Vanessa Bieker Dr. Abram Calderon Dr. Tuyen T. N. Tran Dr. Silke Brand Dr. Leif Dehmelt Prof. Dr. Herbert Waldmann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(14):5311-5316
Macrocyclic natural products (NPs) and analogues thereof often show high affinity, selectivity, and metabolic stability, and methods for the synthesis of NP‐like macrocycle collections are of major current interest. We report an efficient solid‐phase/cyclorelease method for the synthesis of a collection of macrocyclic depsipeptides with bipartite peptide/polyketide structure inspired by the very potent F‐actin stabilizing depsipeptides of the jasplakinolide/geodiamolide class. The method includes the assembly of an acyclic precursor chain on a polymeric carrier, terminated by olefins that constitute complementary fragments of the polyketide section and cyclization by means of a relay‐ring‐closing metathesis (RRCM). The method was validated in the first total synthesis of the actin‐stabilizing cyclodepsipeptide seragamide A and the synthesis of a collection of structurally diverse bipartite depsipeptides. 相似文献
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Synthesis of novel allyl palladium complexes bearing purine based NHC and a water soluble phosphine and their catalytic activity in the Suzuki‐Miyaura coupling in water 下载免费PDF全文
Thomas Scattolin Luciano Canovese Fabiano Visentin Stefano Paganelli Patrizia Canton Nicola Demitri 《应用有机金属化学》2018,32(2)
We have synthesized and fully characterized some novel allyl palladium complexes stabilized by mixed spectator ligands, namely the water soluble sodium 3,3′,3″‐phosphinetriyltribenzenesulfonate, (TPPTS) and three carbenes derived from differently alkylated natural xanthines. In order to explore their potential applications we have tested their catalytic activity in the Suzuki‐Miyaura coupling of para‐bromoacetophenone with phenyl boronic acid, chosen as standard reaction. Only one of the complexes under study displays a remarkable stability in water and catalytic activity. We have therefore undertaken a catalytic investigation. These results are reported in the present paper together with the solid state structural characterization of a silver precursor of the palladium allyl complexes. 相似文献