- New secondary metabolites from Allium victorialis
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Allumines A and B (1 and 2, resp.), two new steroidal alkaloids, and a new cyclopentene derivative, 3, were isolated from the CHCl3-soluble fraction of the whole plant of Allium victorialis. Their structures were elucidated by spectroscopic techniques, including 1D- and 2D-NMR spectroscopy. Copyright
- Khan, Sadia,Fatima, Itrat,Hussain Kazmi, Mehdi,Malik, Abdul
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- Preparation method of propofol and structural analogues of propofol
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The invention relates to a preparation method of propofol and structural analogues of propofol. The preparation method comprises the steps as follows: preparing an intermediate from p-hydroxybenzoic acid and alkyl alcohol as raw materials under the action of a solid acid catalyst, and then preparing a target product by a decarboxylase reaction. The preparation method has the characteristics of being green in synthesis, realizing biotransformation, causing little pollution, producing few by-products and the like, and is suitable for industrial production; the purity of the prepared products such as propofol is 99.6% or higher, which meets various medicinal standards.
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Paragraph 0074-0080
(2017/08/28)
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- A recyclable nanoparticle-supported palladium catalyst for the hydroxycarbonylation of aryl halides in water
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Boomerang catalysis: A catalyst catchrelease system Is established by the noncovalent attachment of a Pd N-heterocyclic carbene complex to graphene-coated magnetic Co nanoparticles. The immobilization by pyrene tags (see scheme; blue) is reversible at elevated temperatures, releasing the homogeneous catalyst. The hydroxycarbonylation of aryl halides is performed in 16 iterative reactions with this highly active catalyst. (Figure Presented)
- Wittmann, Sebastian,Schaetz, Alexander,Grass, Robert N.,Stark, Wendelin J.,Reiser, Oliver
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supporting information; experimental part
p. 1867 - 1870
(2010/06/21)
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- Facile cleavage of ethers in ionic liquid
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Various alkyl ethers were efficiently cleaved by treating them with pyridinium halides in ionic liquid, and the desired products were obtained in excellent yields.
- Cheng, Lili,Aw, Carlin,Ong, Siew Siang,Lu, Yixin
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supporting information; experimental part
p. 2008 - 2010
(2009/08/14)
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- Replacement of the N-terminal tyrosine residue in opioid peptides with 3-(2,6-dimethyl-4-carbamoylphenyl)propanoic acid (Dcp) results in novel opioid antagonists
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3-(2,6-Dimethyl-4-carbamoylphenyl)propanoic acid (Dcp), a 2′,6′-dimethyltyrosine analogue containing a carbamoyl group in place of the hydroxyl function and lacking the amino group, was synthesized. The replacement of Tyr1 in an enkephalin analogue and in dynorphin A(1-11)-NH2 with Dcp resulted in the first opioid peptide-derived antagonists that do not contain a phenolic hydroxyl group at the 1-position residue. The cyclic peptide Dcp-c[D-Cys-Gly-Phe(pNO2)-D-Cys]NH 2 represents a novel, potent μ opioid antagonist.
- Lu, Yixin,Lum, Tze Keong,Augustine, Yoon Wui Leow,Weltrowska, Grazyna,Nguyen, Thi M.-D.,Lemieux, Carole,Chung, Nga N.,Schiller, Peter W.
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p. 5382 - 5385
(2007/10/03)
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- Total synthesis of pterosines B and C via a photochemical key step
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A total synthesis of pterosines B and C is reported. Starting with a fourfold substituted benzene derivative, the introduction of the remaining substituents is mainly based on Sonogashira couplings followed by different transformations of the ethyne moiety. The key step is a photochemical ring-closure of an α-mesyloxy ketone forming the 1-indanone skeleton. Georg Thieme Verlag Stuttgart.
- Wessig, Pablo,Teubner, Janek
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p. 1543 - 1546
(2007/10/03)
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- A simple debenzylation of O-substituted phenol ethers using hydrobromic acid in presence of phase transfer catalyst
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A simple methodology for the debenzylation of ortho substituted phenol ethers in two phase system with aqueous hydrobromic acid in the presence of tetrabutylammonium bromide as a phase transfer catalyst is described.
- Bhalerao,Raju,Neelakantan
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p. 1433 - 1439
(2007/10/02)
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