92808-78-1Relevant articles and documents
Stereodivergent synthesis of piperidine iminosugars 1-deoxy-D-nojirimycin and 1-deoxy-D-altronojirimycin
De Angelis, Martina,Sappino, Carla,Mandic, Emanuela,D'Alessio, Marianna,De Dominicis, Maria Grazia,Sannino, Sara,Primitivo, Ludovica,Mencarelli, Paolo,Ricelli, Alessandra,Righi, Giuliana
, (2020/12/21)
A stereodivergent approach for producing piperidine iminosugars has been developed employing a common optically active precursor. The key steps of the synthetic pathway are the double diastereoselection in the asymmetric dihydroxylation of the suitable ch
Stereoselective Modification of N-(α-Hydroxyacyl)-glycinesters via Palladium-Catalyzed Allylic Alkylation
Horn, Alexander,Kazmaier, Uli
supporting information, p. 4595 - 4599 (2019/06/27)
N-(α-Hydroxyacyl)-glycinesters can be used as excellent nucleophiles in Pd-catalyzed allylic alkylation. The method allows for the stereoselective introduction of a wide range of side chains, including highly functionalized ones. Both diastereomers can be accessed through variation of the reaction conditions. Furthermore, the use of stannylated carbonates introduces vinylstannane motifs, which are eligible for subsequent C-C coupling reactions.
Stereodivergent Hydroboration of Allenes
Nagashima, Yoshiyuki,Sasaki, Keiji,Suto, Takahiro,Sato, Takaaki,Chida, Noritaka
supporting information, p. 1024 - 1028 (2018/03/21)
Full details of a stereodivergent hydroboration of allenes are reported. While hydroboration of an allene with 9-BBN provided a thermodynamically stable (E)-allylic alcohol after oxidative work-up, the reaction of an identical allene with HB(Sia)2 (disiamylborane) formed a (Z)-allylic alcohol as the kinetic product. The developed conditions allowed for the synthesis of trisubstituted olefins in a highly stereoselective fashion, which is known to be challenging. The method was also applied to the stereodivergent synthesis of structural motifs such as skipped dienes and allylbenzenes, which are often embedded in biologically active natural products.
Highly stereoselective peptide modifications through Pd-catalyzed allylic alkylations of chelated peptide enolates
Deska, Jan,Kazmaier, Uli
, p. 6204 - 6211 (2008/02/13)
Deprotonation of peptides in the presence of zinc chloride gives rise to highly reactive nucleophiles that can be subjected to palladium-catalyzed allylic alkylation reactions. Excellent diastereoselectivities are obtained that are nearly independent of the allylic substrate used. By using this protocol, highly functionalized side chains can also be incorporated in excellent yields and selectivities. The stereochemicaloutcome of the reaction is exclusively controlled by the peptide chain as long as terminal π-allyl-palladium complexes are involved. Probably, there is a threefold coordination, at least, ofthe deprotonated peptide chain to the chelating zinc ion. In such metal peptide complexes, one face of the generated enolate is shielded by the side chain of the adjacent amino acid, thus directing the electrophilic attack onto the opposite face. This behavior explains why an S amino acid always generates an R amino acid (and the other way round).
A new diorganozinc-based enantioselective access to truncated D-ribo-phytosphingosine
Ayad, Tahar,Génisson, Yves,Verdu, Alexandre,Baltas, Michel,Gorrichon, Liliane
, p. 579 - 582 (2007/10/03)
The use of a trans α,β-epoxyaldehyde as a precursor of D-ribo-phytosphingosines was studied. The highly stereoselective alkylation of the aldehyde with a diorganozinc reagent was ensured through double asymmetric induction. The regioselective opening of t
New 3'-azido-3'-deoxythymidin-5'-yl O-(4-hydroxyalkyl or -alkenyl or -alkylepoxide) carbonate prodrugs: synthesis and anti-HIV evaluation.
Vlieghe,Clerc,Pannecouque,Witvrouw,De Clercq,Salles,Kraus
, p. 3014 - 3021 (2007/10/03)
New 5'-O-carbonate prodrugs of zidovudine (AZT) have been synthesized in order to enhance its uptake by HIV-1 infected cells, to improve its anti-HIV potency, and to optimize the intramolecular cyclic rearrangement process related to the 5'-O-(4-hydroxybu
Mechanistic study of the ring-enlargement reaction of (3-oxa-2-silacyclopentyl)methyl radicals into 4-oxa-3-silacyclohexyl radicals. Evidence for a pentavalent silicon-bridging radical transition state in 1,2-rearrangement reactions of β-silyl radicals
Shuto, Satoshi,Sugimoto, Isamu,Abe, Hiroshi,Matsuda, Akira
, p. 1343 - 1351 (2007/10/03)
A mechanistic study was performed on a novel radical ring-enlargement reaction of (3-oxa-2-silacyclopentyl)methyl radicals into 4-oxa-3-silacyclohexyl radicals. Two pathways, one via a pentavalent silicon-bridging radical transition state (or intermediate
Selective deprotection of t-butyldiphenylsilyl ethers in the presence of t-butyldimethylsilyl ethers by tetrabutylammonium fluoride, acetic acid, and water
Higashibayashi,Shinko,Ishizu,Hashimoto,Shirahama,Nakata
, p. 1306 - 1308 (2007/10/03)
The selective deprotection of t-butyldiphenylsilyl ethers in the presence of t-butyldimethylsilyl ethers by tetrabutylammonium fluoride, acetic acid, and water has been realize.
Constrained amino acids. The synthesis of glutamine mimetics
Sabol, Jeffrey S.,Flynn, Gary A.,Friedrich, Dirk,Huber, Edward W.
, p. 3687 - 3690 (2007/10/03)
The preparation and utility of conformationally constrained homoserines trans-8a and cis-8b as intermediates for the synthesis of constrained glutamine mimetics trans-1a and cis-1b is presented.
Stereochemical aspects of intramolecular palladium catalysed [3+2] cycloadditions of methylenecyclopropanes
Corlay, Herve,Motherwell, William B.,Pennell, Andrew M. K.,Shipman, Michael,Slawin, Alexandra M. Z.,Williams, David J.,Binger, Paul,Stepp, Michael
, p. 4883 - 4902 (2007/10/03)
The preparation and intramolecular palladium catalysed [3+2] cycloaddition reactions of a range of substrates containing either stereochemically defined 2,3-disubstituted methylenecyclopropanes 3 or acrylate acceptors 12-15 are described. Evidence is presented which supports the hypothesis that these cycloaddition reactions proceed via palladium-trimethylenemethane type intermediates and that the two carbon-carbon bonds are formed in a highly asynchronous manner.
