Synthesis of enantiomerically pure N-(2,3-dihydroxypropyl)arylamides via oxidative esterification

• Akula Raghunadh,
• Satish S More,
• T. Krishna Chaitanya,
• Yadla Sateesh Kumar,
• Suresh Babu Meruva,
• L. Vaikunta Rao and
• U. K. Syam Kumar

Beilstein J. Org. Chem. 2013, 9, 2129–2136, doi:10.3762/bjoc.9.250

• ][6] or (ii) catalytic oxidations with peroxides and chiral transition metal complexes [7][8][9]. The oxidative esterification of aldehydes involving oxidation followed by a C–O or C–N bond formation has received significant synthetic interest of late. Various transition metal complexes are employed

True and masked three-coordinate T-shaped platinum(II) intermediates

• Manuel A. Ortuño,
• Salvador Conejero and
• Agustí Lledós

Beilstein J. Org. Chem. 2013, 9, 1352–1382, doi:10.3762/bjoc.9.153

• Scope of this review Reaction intermediates are transient species able to undergo transformations along chemical processes. Electron deficient transition-metal complexes with vacant coordination sites are well-suited to play such a role. Coordinatively and electronically unsaturated species have often

• been invoked as crucial intermediates in reactions involving late transition-metal complexes. Ligand dissociation, forming intermediates with open coordination sites, has been proposed as the initial step in many reactions involving square-planar d8 organometallic complexes [1]. Four-coordinate square

• ][30] is usually explained as an intramolecular 3-center-2-electron interaction between a metal M and a C–H bond. This type of contact is a recurrent event in unsaturated transition-metal complexes [31] and it can be characterized by structural and spectroscopic techniques [29][30] together with

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• consider this approach as an example of the metal-free activation of NHIs, as no further addition of transition-metal complexes is required. Galli and co-workers [27][28] significantly contributed over the years to the interpretation of the reaction mechanism by comparing NHPI and many other NHDs (Figure 1

• converting primary hydroxyl groups to the corresponding carboxylic functions, maintaining the original backbone of the polysaccharide, is of major interest for different applications [46][47]. By comparing different activation approaches, including transition-metal complexes, Coseri found that the NHPI/AQ

• -catalysts, they are activated to the corresponding N-oxyl radical species and become able to promote radical chains, involving molecular oxygen, directly or indirectly. Most of the examples reported in the literature describe the use of these N-hydroxy derivatives in the presence of transition-metal

Transition-metal and organocatalysis in natural product synthesis

• David Yu-Kai Chen and
• Dawei Ma

Beilstein J. Org. Chem. 2013, 9, 1192–1193, doi:10.3762/bjoc.9.134

• discovery of novel transitional-metal complexes and their associated chemical transformations, and rediscovery of the unprecedented reactivity of previously documented transition-metal complexes with subtle changes in the reaction conditions and the reacting substrate have been extremely fruitful since the

Photoinduced synthesis of unsymmetrical diaryl selenides from triarylbismuthines and diaryl diselenides

• Yohsuke Kobiki,
• Shin-ichi Kawaguchi,
• Takashi Ohe and
• Akiya Ogawa

Beilstein J. Org. Chem. 2013, 9, 1141–1147, doi:10.3762/bjoc.9.127

• diaryl selenides from triarylbismuthines and diaryl diselenides has been developed. Although the arylation reactions with triarylbismuthines are usually catalyzed by transition-metal complexes, the present arylation of diaryl diselenides with triarylbismuthines proceeds upon photoirradiation in the

• ][24][25][26][27][28][29][30][31][32]. Most of these methods use coupling reactions catalyzed by transition-metal complexes. To avoid the contamination of product selenides with transition-metals, the development of synthetic methods for unsymmetrical diaryl selenides in the absence of transition-metal

Synthesis, photophysical and electrochemical characterization of terpyridine-functionalized dendritic oligothiophenes and their Ru(II) complexes

• Amaresh Mishra,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2013, 9, 866–876, doi:10.3762/bjoc.9.100

• oligomers and polymers are amongst the best-studied π-conjugated systems in the past few decades because of their tunable optoelectronic properties [6][7][8]. Furthermore, transition-metal complexes offer significant advantages such as long-lived luminescent excited states, high chemical and photochemical

• has found applications in opto-electronic devices and nanotechnology [11][12][13]. The stability of these transition-metal complexes is generally attributed to the σ-donor/π-acceptor character of the dative metal–nitrogen bond. These Ru(II) complexes possess various important photophysical features

• past years, a large number of luminescent dendrimers based on polynuclear transition-metal complexes have been developed as promising materials for the study of unidirectional energy transfer and multielectron-transfer processes as well as for light-harvesting applications [19]. Among the polypyridine

Synthesis and structure of trans-bis(1,4-dimesityl-3-methyl-1,2,3-triazol-5-ylidene)palladium(II) dichloride and diacetate. Suzuki–Miyaura coupling of polybromoarenes with high catalytic turnover efficiencies

• Jeelani Basha Shaik,
• Venkatachalam Ramkumar,
• Babu Varghese and
• Sethuraman Sankararaman

Beilstein J. Org. Chem. 2013, 9, 698–704, doi:10.3762/bjoc.9.79

• -metal and lanthanide metal chemistry [1][10][11]. Over the past few years they have gradually replaced the conventional phosphane ligands. The transition-metal complexes of these versatile ligands have been shown to be excellent catalysts for various organic transformations [9][10][11][12][13][14

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

• ca. 50% from 3d to 4d and also from 4d to 5d) relative to analogous 3d compounds and is generally much greater than the spin pairing energy; hence virtually all 4d and 5d transition metal complexes show LS behavior. Spin transition seems to occur predominantly for six-coordinate iron(II) complexes

Highly enantioselective access to cannabinoid-type tricyles by organocatalytic Diels–Alder reactions

• Stefan Bräse,
• Nicole Volz,
• Franziska Gläser and
• Martin Nieger

Beilstein J. Org. Chem. 2012, 8, 1385–1392, doi:10.3762/bjoc.8.160

• fine chemicals, were either transition-metal complexes or enzymes. In the past few years, however, organocatalysis has emerged as an alternative approach for the catalytic production of enantiomerically pure organic compounds [15][16]. These organocatalysts have several important advantages. They are

Synthesis and structure of tricarbonyl(η⁶-arene)chromium complexes of phenyl and benzyl D-glycopyranosides

• Thomas Ziegler and
• Ulrich Heber

Beilstein J. Org. Chem. 2012, 8, 1059–1070, doi:10.3762/bjoc.8.118

• transition-metal complexes of arenes have been prepared, characterized and described in the literature. Among the multitude of transition-metal complexes of aromatic compounds, however, only tricarbonyl(η6-arene)chromium compounds are widely used for organic syntheses [2][3][4]. This is due to the fact that

Low-generation dendrimers with a calixarene core and based on a chiral C₂-symmetric pyrrolidine as iminosugar mimics

• Marco Marradi,
• Stefano Cicchi,
• Francesco Sansone,
• Alessandro Casnati and
• Andrea Goti

Beilstein J. Org. Chem. 2012, 8, 951–957, doi:10.3762/bjoc.8.107

• metal-ion effect on the organisation of iminosugars and on the rigidification of the calixarene scaffold, but also to exploit the ability of these chiral ligands to enantioselectively recognise chiral salts [37] or the ability of their transition-metal complexes to catalyse enantioselective syntheses

Syntheses and applications of furanyl-functionalised 2,2’:6’,2’’-terpyridines

• Jérôme Husson and
• Michael Knorr

Beilstein J. Org. Chem. 2012, 8, 379–389, doi:10.3762/bjoc.8.41

• as N-donor ligands toward numerous main-group, transition-metal and lanthanide cations [3]. Coordination compounds LnM(tpy)m (n = 0–4; m = 1,2) ligated with terpyridine derivatives form stable assemblies due to the thermodynamic chelate effect. In the case of transition metal complexes, the σ-donor/π

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• + to 3a and 3k [48]. Again, Na+ was bound preferentially, with computer models suggesting that this was due to the depth to which the cation was drawn into the macrocyclic cavity when in the cone conformer. 4.1.3 Transition-metal complexes: The first example of transition-metal binding to an oxacalix[3

Recent developments in gold-catalyzed cycloaddition reactions

• Fernando López and
• José L. Mascareñas

Beilstein J. Org. Chem. 2011, 7, 1075–1094, doi:10.3762/bjoc.7.124

• precursors presenting suitable electronic properties. In this regard, transition metal complexes, owing to their multiple coordination and activation properties, offer excellent opportunities for the discovery of new cycloaddition alternatives, and in many cases they can be used in a catalytic manner

Triazole–Au(I) complex as chemoselective catalyst in promoting propargyl ester rearrangements

• Dawei Wang,
• Yanwei Zhang,
• Rong Cai and
• Xiaodong Shi

Beilstein J. Org. Chem. 2011, 7, 1014–1020, doi:10.3762/bjoc.7.115

• . Keywords: allene; chemoselectivity; gold catalysis; ligand effect; organometallic; Introduction The past decade has seen rapid growth in the use of homogeneous gold catalysis for conducting powerful organic transformations [1][2][3][4][5][6][7][8][9]. Like many other transition metal complexes, the

When cyclopropenes meet gold catalysts

• Frédéric Miege,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2011, 7, 717–734, doi:10.3762/bjoc.7.82

• in the presence of electrophilic transition metal complexes. Shi et al. initially suggested that the formation of 22 preferentially occurs with a rather bulky electrophile such as Cu(OTf)2 to avoid repulsion with the aryl group at C2. Conversely, a Brønsted acid (generated by reaction of BF3·OEt2

Achiral bis-imine in combination with CoCl₂: A remarkable effect on enantioselectivity of lipase-mediated acetylation of racemic secondary alcohol

• K. Arunkumar,
• M. Appi Reddy,
• T. Sravan Kumar,
• B. Vijaya Kumar,
• K. B. Chandrasekhar,
• P. Rajender Kumar and
• Manojit Pal

Beilstein J. Org. Chem. 2010, 6, 1174–1179, doi:10.3762/bjoc.6.134

• preliminary results on the synthesis and identification of a novel ligand for this process (Scheme 1) and its application in the preparation of the known drug rivastigmine [14]. While the uses of bis-imine/transition-metal complexes have been reported for the enantioselective synthesis of chiral compounds [15

Light-induced olefin metathesis

• Yuval Vidavsky and
• N. Gabriel Lemcoff

Beilstein J. Org. Chem. 2010, 6, 1106–1119, doi:10.3762/bjoc.6.127

• -defined early transition metal complexes for photocatalysed ROMP (PROMP) 3 and 4 (Figure 1) was published by van der Schaaf, Hafner, and Mühlebach [59]. Complexes 3 and 4 displayed reasonable thermal stability in solution (no decomposition was observed after 1 d at 80 °C), but were moisture sensitive and

A perfluorocyclopentene based diarylethene bearing two terpyridine moieties – synthesis, photochemical properties and influence of transition metal ions

• Falk Wehmeier and
• Jochen Mattay

Beilstein J. Org. Chem. 2010, 6, No. 53, doi:10.3762/bjoc.6.53

• [M−3 PF6]+, 2352 [M−2 PF6]+, 2497 [M−PF6]+. ESI-MS (positive mode, MeCN, m/z): 2497 ([M−PF6]+). ESI-MS (negative mode, MeCN, m/z): 2787 ([M+PF6]−) [19]. General procedures for transition metal complexes of 3,3′-(perfluorocyclopent-1-ene-1,2-diyl)bis(2-methyl-6-(4-(2,2′:6′,2″-terpyridin-4′-yl)phenyl

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

Can we measure catalyst efficiency in asymmetric chemical reactions? A theoretical approach

• Shaimaa El-Fayyoumy,
• Matthew H. Todd and
• Christopher J. Richards

Beilstein J. Org. Chem. 2009, 5, No. 67, doi:10.3762/bjoc.5.67

• catalytic efficiency. Keywords: asymmetric; catalysis; enzymes; organocatalysis; transition metal complexes; Introduction The preferential formation of one enantiomer of a molecule via asymmetric catalysis remains one of the most challenging and exciting areas of academic and industrial research in

Functional properties of metallomesogens modulated by molecular and supramolecular exotic arrangements

• Alessandra Crispini,
• Mauro Ghedini and
• Daniela Pucci

Beilstein J. Org. Chem. 2009, 5, No. 54, doi:10.3762/bjoc.5.54

• multifunctional soft materials, with higher performance than classical liquid crystals. Our interest in the synthesis of metallomesogens and their wide use in the field of material science, coupled with the fact that transition metal complexes have potential antitumor activity, led us to believe that a great