- Preparation of α-amino acids by oxidative oxazoline-oxazinone rearrangement-hydrogenation (OOOH). Scope and limitations
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The range and scope of the oxidative oxazoline-oxazinone rearrangement-hydrogenation sequence (OOOH)-a short, direct asymmetric synthesis of α-amino acids from carboxylic acids-was explored. The highest yet reported diastereoselectivity for hydrogenation of the oxazinone C=N bond (d.r.=>80:1) is disclosed and rationalized with the aid of ab initio molecular calculations.
- Liu, Chaomin,Molinski, Tadeusz F.
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supporting information; experimental part
p. 2022 - 2027
(2011/11/29)
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- QUINOLINE AND QUINOXALINE DERIVATIVES AS INHIBITORS OF KINASE ENZYMATIC ACTIVITY
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Compounds of formula (IA) or (IB), are inhibitors of aurora kinase activity: Formula (IA), (IB) wherein -L1Y1-[CH2]z- is a linker radical wherein Y1, L1 and z are as defined in the claims; R6 is C1-C4alkoxy, hydrogen or halo; W represents a bond, -CH2-, -O-, -S-, -S(=O)2-, or -NR5- where R5 is hydrogen or C1-C4 alkyl; Q is =N-, =CH- or =C(X1)- wherein X1 is cyano, cyclopropyl or halo; linker radicals L2 are as defined in the claims; R is a radical of formula (X) or (Y): wherein R1 is a carboxylic acid group (-COOH), or an ester group which is hydrolysable by one or more intracellular carboxylesterase enzymes to a carboxylic acid group; R4 is hydrogen; or optionally substituted C1-C6 alkyl, C3-C7 cycloalkyl, aryl, aryl(C1-C6 alkyl)-, heteroaryl, heteroaryl(C1-C6 alkyl)-, -(C=O)R3, -(C=O)OR3, or -(C=O)NR3 wherein R3 is hydrogen or optionally substituted (C1-C6)alkyl, C3-C7 cycloalkyl, aryl, aryl(C1-C6 alkyl)-, heteroaryl, or heteroaryl(C1-C6 alkyl)-; R41 is hydrogen or optionally substituted C1-C6 alkyl; and D is a monocyclic heterocyclic ring of 5 or 6 ring atoms.
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Page/Page column 127-128
(2008/06/13)
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- New cyclohexadienone derivatives: Preparation and chiral discrimination in high-pressure diels - Alder cycloadditions
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A wide range of cyclohexadienones has been synthesised in order to study their reactivity and their regio- and stereoselectivity with the enantiopure diene 1 under high-pressure conditions. Computational investigations were used to point out some paramete
- Tran-Huu-Dau, Marie-Elise,Wartchow, Rudolf,Winterfeldt, Ekkehard,Wong, Yung-Sing
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p. 2349 - 2369
(2007/10/03)
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- Highly efficient and flexible total synthesis of coelenterazine
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A new total synthesis of the bioluminescent chromophore coelenterazine 1 is described.
- Keenan, Martine,Jones, Keith,Hibbert, Frank
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p. 323 - 324
(2007/10/03)
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- Analogues of capsaicin with agonist activity as novel analgesic agents; structure-activity studies. 1. The aromatic 'A-region'
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A series of analogues of capsaicin, the pungent principle of chilli peppers, was synthesized and tested in assays for capsaicin-like agonism in vitro. The results of these assays were compared with activities in an acute nociceptive model and a correlation was observed which established that the results of these in vitro assays were predictive of analgesia. Using a modular approach the structure-activity profile of specific regions of capsaicin congeners was established using an in vitro assay measuring 45Ca2+ uptake into neonatal rat dorsal root ganglia neurones. Substituted benzylnonanamides 2a-z and N-octyl-substituted phenylacetamides 4a-v were made to test the requirements for activity in the aromatic 'A-region' of the molecule. Compounds with the natural substitution pattern (2b and 4c) and the corresponding catechols (2i and 4g) were the most potent, although the catechols were less potent in vivo. Other substitution patterns have reduced activity. These results have established stringent structural requirements for capsaicin-like activity in this part of the molecule.
- Walpole,Wrigglesworth,Bevan,Campbell,Dray,James,Perkins,Reid,Winter
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p. 2362 - 2372
(2007/10/02)
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- Penam derivatives and salts thereof, and antibacterial agent comprising the same
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A penam derivative represented by the following general formula or a salt thereof: STR1 wherein R1 represents a hydrogen atom, an amino-protecting group or an acyl group; R2 represents a hydrogen atom or a lower alkyl group; R3
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