Abstract:
:The straightforward synthesis of a series of enantiomerically pure Lewis basic amides by simple condensation of commercially available enantiopure diamines with picolinic acid is reported. These compounds were shown to promote the enantioselective reduction of ketoimines with trichlorosilane. Working with the model substrate N-phenyl benzophenone imine, the new organocatalysts led to the formation of the corresponding amine, with excellent chemical efficiency (up to 99% chemical yield) and good stereoselectivity (up to 73% ee). Up to 83% of enantioselectivity was reached in the reduction of differently substituted imines.
journal_name
Chiralityjournal_title
Chiralityauthors
Guizzetti S,Benaglia M,Cozzi F,Rossi S,Celentano Gdoi
10.1002/chir.20615subject
Has Abstractpub_date
2009-01-01 00:00:00pages
233-8issue
1eissn
0899-0042issn
1520-636Xjournal_volume
21pub_type
杂志文章相关文献
CHIRALITY文献大全abstract::Ninety isolates of microorganisms belonging to different taxonomical groups (30 bacteria, 20 yeast, and 40 fungi) were previously isolated from various samples. These isolates were screened as reducing agents for acetophenone 1a to phenylethanol 2a. It was found that the isolate EBK-10 was the most effective biocataly...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20846
更新日期:2010-10-01 00:00:00
abstract::A simple, green, and direct three-component condensation of acetophenone, aromatic aldehydes with 3-oxo-N-phenylbutanamide (acetoacetanilide) to generate some novel (1S,6R)/(1R,6S)-2-oxo-N,4,6-triarylcyclohex-3-enecarboxamide derivatives was carried out over K2 CO3 (10 mol%) with high efficiency in water/ethanol as gr...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22653
更新日期:2016-11-01 00:00:00
abstract::The simultaneous disposition of fenoprofen enantiomers in synovial fluid and plasma was studied in 11 patients with arthritis and chronic knee effusions treated with a single oral dose of 600 mg rac-fenoprofen. A plasma sample and a synovial fluid sample were collected simultaneously from each patient up to 16 h after...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20374
更新日期:2007-05-05 00:00:00
abstract::Despite that a number of experimental and theoretical investigations have been carried out to determine the structure of trialanine in water, the reported populations of polyproline II (PPII) and β-strand conformers vary and were found to be dependent on which spectroscopic method was used. Such discrepancies are due ...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20870
更新日期:2010-01-01 00:00:00
abstract::(3SR,4RS)-3,4-Epoxypiperidine-4-carboxylic acid (isoguvacine oxide) is a potent and specific GABAA receptor agonist. Isoguvacine oxide, originally designed as a potentially alkylating agonist, turned out to interact with the GABAA receptor in a fully reversible manner. The protected form of isoguvacine oxide, benzyl (...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530070608
更新日期:1995-01-01 00:00:00
abstract::Plasmonic nanoparticles (NPs) adsorbing onto helical bacteria can lead to formation of NP helicoids with micron scale pitch. Associated chiroptical effects can be utilized as bioanalytical tool for bacterial detection and better understanding of the spectral behavior of helical self-assembled structures with different...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.23225
更新日期:2020-07-01 00:00:00
abstract::After alkylation of a fraction of the total alpha-adrenoreceptors by phenoxybenzamine in rat vas deferens, the dissociation constants of (-)- and (+)-epinephrine in functional studies were 7 X 10(-7) M and 2 X 10(-5) M, respectively. In the adrenoreceptor-containing tissue fraction, when 3H-labeled WB4101 was used as ...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530010106
更新日期:1989-01-01 00:00:00
abstract::The novel chiral spirobipyridopyrans 1 and 2 were synthesized by the acid catalyzed aldol type condensation of 5-deoxypyridoxal with the appropriate ketone and subsequent reaction of the resulting pyrylium salt with base. The indolinospiropyridopyrans 3-5, which contain the modified B(6) unit, were prepared by aldol r...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/1520-636X(2001)13:2<81::AID-CHIR1002>3.0.C
更新日期:2001-02-01 00:00:00
abstract::This article describes a very useful extension of an unique column switching technique called "Simulated Moving Columns" (SMC) that was previously reported for chiral high performance liquid chromatography (HPLC) (Zhang and McConnell, Journal of Chromatography A 2004;1028:227-238). SMC uses two or three short chiral c...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20409
更新日期:2007-09-01 00:00:00
abstract::There is a great deal of current interest in the role and importance of chirality in the development of new drugs, but little attention is being paid to the stereochemistry of older drugs. Indeed, many older chiral drugs were introduced without adequate information on their stereochemical identity or composition. We h...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530030103
更新日期:1991-01-01 00:00:00
abstract::A systematic and comprehensive study of the conformational spaces of the Cinchona alkaloids quinine, quinidine, cinchonine, cinchonidine, epiquinine, epiquinidine, epicinchonine, and epicinchonidine using the semiempirical PM3 method is described. The results were analyzed in terms of syn/anti and open/closed/hindered...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.10265
更新日期:2003-08-01 00:00:00
abstract::Symmetry breaking by photons, electrons, and molecular interactions lies at the heart of many important problems as varied as the origin of homochiral life to enantioselective drug production. Herein we report a system in which symmetry breaking can be induced and measured in situ at the single-molecule level using sc...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22096
更新日期:2012-12-01 00:00:00
abstract::The synthesis of the eight stereoisomers of muscarine has been efficiently accomplished by utilizing the two enantiomers of lactic esters as starting material. The synthetic strategy is based on a SnCl4-catalyzed addition of allyltrimethylsilane to O-protected lactic aldehydes followed by an iodocyclization process. A...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530040406
更新日期:1992-01-01 00:00:00
abstract::The use of stereodynamic probes is becoming one of the leading strategies for the fast and effective determination of enantiomeric excess. Recently, we reported a series of novel molecular architectures based on a modified tris(2-pyridylmethyl)amine complex (TPMA), which are able to amplify the electronic CD, in the c...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22780
更新日期:2018-01-01 00:00:00
abstract::The first direct asymmetric synthetic preparation of trifluoro-1-(indol-3-yl)ethanols (TFIEs) is described by an enantioselective organocatalytic method from indoles and inexpensive trifluoroacetaldehyde methyl hemiacetal. The reaction is catalyzed by hydroquinine to produce TFIEs in an almost quantitative yield and w...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20982
更新日期:2011-09-01 00:00:00
abstract::We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation using N-BOC protected...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/(SICI)1520-636X(1997)9:5/6<529::AID-CHIR20
更新日期:1997-01-01 00:00:00
abstract::The chiral separation by counter-current chromatography has made great progress in the past three decades. It has become increasingly popular in the field of chiral separation, and many applications have been introduced during the last years. This review mainly focuses on the current topics, applications, and trends i...
journal_title:Chirality
pub_type: 杂志文章,评审
doi:10.1002/chir.23262
更新日期:2020-10-01 00:00:00
abstract::This paper reports the enantioseparation of β-hydroxy-1,2,3-triazole derivatives, which present a broad range of biological properties, by supercritical fluid chromatography (SFC) and high-performance liquid chromatography techniques (HPLC). Polysaccharide-based chiral columns (cellulose and amylose) were used to eval...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22851
更新日期:2018-07-01 00:00:00
abstract::Two "click" binaphthyl chiral stationary phases were synthesized and evaluated by liquid chromatography. Their structures incorporate S-(-)-1,1'-binaphthyl moiety as the chiral selector and 1,2,3-triazole ring as the spacer. These chiral stationary phases (CSPs) allowed the efficient resolution for a wide range of rac...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22039
更新日期:2012-05-01 00:00:00
abstract::Plants and fungi are seemingly inexhaustible sources of interesting natural products with remarkable structural and biological diversity. One of the most important groups is the terpenes, ubiquitous natural products that are generated by 2 now well-established biosynthetic pathways: the older mevalonate and the more r...
journal_title:Chirality
pub_type: 杂志文章,评审
doi:10.1002/chir.23009
更新日期:2018-10-01 00:00:00
abstract::Four racemic esters of (1R*,7aR*)-3,6,7,7a-tetrahydro-1-hydroxy-7a-methyl-1H-inden-5(2H)-one were prepared and subjected to hydrolysis with two types of hydrolases, including alcalase and three lipases. Alcalase and lipase showed opposite enantiopreference on these esters. Based on this result, we developed a gram-sca...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20023
更新日期:2004-05-05 00:00:00
abstract::The chiral squaramide catalysts (8-15) were synthesized, and their catalytic efficiency in the enantioselective conjugate addition of pyrazolones to nitroalkenes was described. This protocol provides excellent chemical yields (up to 93%) of chiral 5-methyl-4-(2-nitro-1-arylethyl)pyrazol-3-ol derivatives with high enan...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.23295
更新日期:2021-01-11 00:00:00
abstract::Integrating spheres are widely used with UV-Vis and occasionally with infrared spectrophotometers to measure different types of samples, either in transmission mode (scattered transmission accessories) or in total/diffuse reflectance mode. We built a prototype sphere of the demountable type, which fits easily the samp...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/(SICI)1520-636X(2000)12:4<291::AID-CHIR16>
更新日期:2000-05-01 00:00:00
abstract::The modern use of preparative chromatography in pharmaceutical development is illustrated by the case of a recent preclinical candidate from these laboratories. The synthesis of the candidate employed a coupling of two enantiopure intermediates, each of which could be resolved using preparative chiral chromatography. ...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20378
更新日期:2007-09-01 00:00:00
abstract::Enantioseletive toxicities of chiral pesticides have become an environmental concern recently. In this study, we evaluated the enantiomeric separation of salithion on a suite of commercial chiral columns and assessed the toxicity of enantiomers toward butyrylcholinesterase and Daphnia magna. Satisfactory separations o...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20690
更新日期:2009-11-01 00:00:00
abstract::Two new carotenoids, sapotexanthin 5,6-epoxide and sapotexanthin 5,8-epoxide, have been isolated from the ripe fruits of red mamey (Pouteria sapota). Sapotexanthin 5,6-epoxide was also prepared by partial synthesis via epoxidation of sapotexanthin, and the (5R,6S) and (5S,6R) stereoisomers were identified by high-perf...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.23206
更新日期:2020-05-01 00:00:00
abstract::A series of silica-supported proline-based peptides were synthesized and applied as catalysts for direct asymmetric intermolecular aldol reactions. Among these, a peptide with two L-proline units was found to be the most efficient one for the asymmetric aldol reactions between acetone and aromatic aldehydes. The react...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20603
更新日期:2009-04-01 00:00:00
abstract::Planar 2(5H)-furanones substituted at C4 with a chiral pyrrolidinyl group show CD spectra which are apparently due to the distortion of the C4-N1 bond of sp2 character from the plane defined by the 2(5H)-furanone ring atoms and/or due to the presence of substituents in the pyrrolidine ring. This is a new, previously n...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20059
更新日期:2004-08-01 00:00:00
abstract::1alpha,25-Dihydroxyvitamin D(3) (1alpha,25(OH)2D3) has been shown to modulate not only proliferation and differentiation, but also apoptosis in malignant cells, indicating that it could be useful for the treatment of cancer and psoriasis. However, little information has been available on the binding conformation of th...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.1046
更新日期:2001-07-01 00:00:00
abstract::Glutathione (GSH) conjugation of the chiral compound 2-bromo-3-phenylpropionic acid (BPP) was studied in vitro and in the rat in vivo. GSH conjugation of BPP, catalyzed by a mixture of glutathione-S-transferases (GST's) from rat liver cytosol in vitro, was stereoselective: at a substrate concentration of 250 microM, (...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530040702
更新日期:1992-01-01 00:00:00