96606-95-0Relevant academic research and scientific papers
Synthetic Studies Toward the Skyllamycins: Total Synthesis and Generation of Simplified Analogues
Giltrap, Andrew M.,Haeckl, F. P. Jake,Kurita, Kenji L.,Linington, Roger G.,Payne, Richard J.
, p. 7250 - 7270 (2018/06/01)
Herein, we report our synthetic studies toward the skyllamycins, a highly modified class of nonribosomal peptide natural products which contain a number of interesting structural features, including the extremely rare α-OH-glycine residue. Before embarking on the synthesis of the natural products, we prepared four structurally simpler analogues. Access to both the analogues and the natural products first required the synthesis of a number of nonproteinogenic amino acids, including three β-OH amino acids that were accessed from the convenient chiral precursor Garner's aldehyde. Following the preparation of the suitably protected nonproteinogenic amino acids, the skyllamycin analogues were assembled using a solid-phase synthetic route followed by a final stage solution-phase cyclization reaction. To access the natural products (skyllamycins A-C) the synthetic route used for the analogues was modified. Specifically, linear peptide precursors containing a C-terminal amide were synthesized via solid-phase peptide synthesis. After cleavage from the resin the N-terminal serine residue was oxidatively cleaved to a glyoxyamide moiety. The target natural products, skyllamycins A-C, were successfully prepared via a final step cyclization with concomitant formation of the unusual α-OH-glycine residue. Purification and spectroscopic comparison to the authentic isolated material confirmed the identity of the synthetic natural products.
Palladium-Catalyzed, Norbornene-Mediated, ortho-Amination ipso-Amidation: Sequential C-N Bond Formation
Whyte, Andrew,Olson, Maxwell E.,Lautens, Mark
, p. 345 - 348 (2018/01/27)
A palladium-catalyzed, norbornene-mediated ortho- and ipso-C-N bond-forming Catellani reaction is reported. This reaction proceeds through a sequential intermolecular amination followed by intramolecular cyclization of a tethered amide. The products, ortho-aminated dihydroquinolinones, were generated in moderate to good yields and are present in bioactive molecules. This work highlights the challenge of competing intra- vs intermolecular palladium-catalyzed processes.
Total Synthesis of Skyllamycins A–C
Giltrap, Andrew M.,Haeckl, F. P. Jake,Kurita, Kenji L.,Linington, Roger G.,Payne, Richard J.
supporting information, p. 15046 - 15049 (2017/10/31)
The skyllamycins are a family of highly functionalized non-ribosomal cyclic depsipeptide natural products which contain the extremely rare α-OH-glycine functionality. Herein the first total synthesis of skyllamycins A–C is reported, together with the biofilm inhibitory activity of the natural products. Linear peptide precursors for each natural product were prepared through an efficient solid-phase route incorporating a number of synthetic modified amino acids. A novel macrocyclization step between a C-terminal amide and an N-terminal glyoxylamide moiety served as a key transformation to install the unique α-OH-glycine unit and generate the natural products in the final step of the synthesis.
Copper-catalyzed cross-coupling of O -alkyl hydroxamates with aryl iodides
Kukosha, Tatyana,Trufilkina, Nadezhda,Belyakov, Sergey,Katkevics, Martins
, p. 2413 - 2423 (2012/09/07)
N-Aryl-O-alkylhydroxamic acid derivatives were prepared by copper-catalyzed cross-coupling of hydroxamates with aryl iodides. The reaction conditions are compatible with standard hydroxy-protecting groups on the hydroxylamine moiety and are applicable to
On homogeneous gold/palladium catalytic systems
Hashmi, A. Stephen K.,Lothschuetz, Christian,Doepp, Rene,Ackermann, Martin,De Buck Becker, Janosc,Rudolph, Matthias,Scholz, Christian,Rominger, Frank
, p. 133 - 147 (2012/04/10)
Two substrates containing an aryl iodide and an allenoate ester were prepared and the goldinduced cycloisomerisation to vinylgold(I) species and their proto-deauration as well as the intramolecular palladium-catalysed cross-coupling reactions were investigated. Switching to catalytic amounts of gold and palladium and stoichiometric amounts of silver did indeed furnish the product of a cycloisomerisation/ intramolecular cross-coupling. Control experiments revealed that silver cannot substitute for gold or palladium in these reactions, but a different palladium catalyst in a different oxidation state also afforded the cycloisomerisation/intramolecular crosscoupling products in only slightly reduced yields. By ICP analysis the palladium was shown to contain gold only at the sub-ppm level. This shows how carefully results obtained with such systems have to be interpreted. Then a series of allylic and benzylic o-alkynylbenzoates were investigated in gold-and palladium-catalysed reactions. For esters of benzyl alcohol and cinnamyl alcohol no palladium co-catalyst was needed for the conversion. All reagents were thoroughly checked for palladium traces by ICP analysis in order to thoroughly exclude a gold/palladium cocatalysis. Optimisation of the gold complex, counter ion and solvent showed that gold(I) isonitrile precatalysts and silver triflate as activator in dioxane are suitable to convert a number of substrates with aryl, alkyl and even cyclopropyl substituents. Crossover experiments proved an intermolecular allyl transfer.
Discovery of potent and selective agonists for the free fatty acid receptor 1 (FFA1/GPR40), a potential target for the treatment of type II diabetes
Christiansen, Elisabeth,Urban, Christian,Merten, Nicole,Liebscher, Kathrin,Karlsen, Kasper K.,Hamacher, Alexandra,Spinrath, Andreas,Bond, Andrew D.,Drewke, Christel,Ullrich, Susanne,Kassack, Matthias U.,Kostenis, Evi,Ulven, Trond
supporting information; experimental part, p. 7061 - 7064 (2009/11/30)
A series of 4-phenethynyldihydrocinnamic acid agonists of the free fatty acid receptor 1 (FFA1) has been discovered and explored. The preferred compound 20 (TUG-424, EC50 = 32 nM) significantly increased glucose-stimulated insulin secretion at 100 nM and may serve to explore the role of FFA1 in metabolic diseases such as diabetes or obesity.
The Photo-Dehydro-Diels-Alder (PDDA) reaction - A powerful method for the preparation of biaryls
Wessig, Pablo,Mueller, Gunnar,Pick, Charlotte,Matthes, Annika
, p. 464 - 477 (2007/12/27)
The photochemically initiated dehydro-Diels-Alder (PDDA) reaction is an efficient and versatile method for the preparation of biaryls. The ring closure may take place both inter- and intramolecularly, of which the intramolecular variant is more productive
AROMATIC OXYPHENYL AND AROMATIC SYLFANYLPHENYL DERIVATIVES
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Page 45, (2008/06/13)
The present invention relates to compounds of formula I wherein the substituents are as defined below. The compounds of formula I are useful for the treatment of diseases such as schizophrenia, including both the positive and the negative symptoms of schizophrenia and other psychoses.
Carbopalladation of nitriles: Synthesis of benzocyclic ketones and cyclopentenones via Pd-catalyzed cyclization of ω-(2-iodoaryl)alkanenitriles and related compounds
Pletnev, Alexandre A.,Larock, Richard C.
, p. 9428 - 9438 (2007/10/03)
An efficient procedure for the synthesis of 2,2-disubstituted benzocyclic ketones by intramolecular carbopalladation of nitriles has been developed. The cyclization of substituted 3-(2-iodoaryl)-propanenitriles affords indanones in high yields. The reaction is compatible with a wide variety of functional groups. This methodology has been extended to the synthesis of tetralones and cyclopentenones.
The effect of vinyl esters on the enantioselectivity of the lipase-catalysed transesterification of alcohols
Kawasaki, Masashi,Goto, Michimasa,Kawabata, Shigeki,Kometani, Tadashi
, p. 585 - 596 (2007/10/03)
The enantioselectivity of the lipase from Pseudomonas cepacia (PCL) in the transesterification of 2-phenyl-1-propanol 1 was studied using a series of vinyl 3-arylpropanoates as acyl donors. The most enantioselective transesterification reaction of the alcohol was attained by using vinyl 3-(p-iodophenyl)- or 3-(p-trifluoromethylphenyl)propanoates, with enantiomer ratios, E, of 116 and 138, respectively. Vinyl 3-phenylpropanoate was also effective for the resolution of 1 mediated by lipases from P. fluorescens and porcine pancreas and for the PCL-catalysed transesterification of several 2-phenyl-1-alkanols. The enantiomeric resolution of 1 was practically carried out by the first enantioselective transesterification using PCL and vinyl 3-(p-iodophenyl)propanoate to afford (R)-1 and then the enantioselective hydrolysis of the resultant ester to afford (S)-1.
