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

• . Moreover, recent experimental and theoretical reports are analyzed, which suggest the involvement of such intermediates in reaction mechanisms, particularly C–H bond-activation processes. Keywords: C–H bond activation; intermediate; platinum(II); reactive intermediates; three-coordinate; T-shaped; Review

• large number of reaction mechanisms. A review concerning dissociative pathways in Pt(II) complexes was published in 1990 [113]. Due to both the low electron count and the presence of a vacant site in the coordination sphere, T-shaped Pt(II) species are suitable intermediates in ligand-exchange and bond

Copper-catalyzed aerobic aliphatic C–H oxygenation with hydroperoxides

• Pei Chui Too,
• Ya Lin Tnay and
• Shunsuke Chiba

Beilstein J. Org. Chem. 2013, 9, 1217–1225, doi:10.3762/bjoc.9.138

• 1,5-H radical shift. Aliphatic C–H oxidation with hydroperoxides. Proposed reaction mechanisms for the formation of 2a, 3a, and 4a. Proposed reaction mechanisms for the formation of 5 and 6. The reaction of secondary hydroperoxide 1o. 1,4-Dioxygenation of alkanes. Aerobic 1,4-dioxygenation of alkanes

Gold-catalyzed oxycyclization of allenic carbamates: expeditious synthesis of 1,3-oxazin-2-ones

• Benito Alcaide,
• Pedro Almendros,
• M. Teresa Quirós and
• Israel Fernández

Beilstein J. Org. Chem. 2013, 9, 818–826, doi:10.3762/bjoc.9.93

• gold-catalyzed synthetic routes to 1,3-oxazinan-2-ones (kinetically controlled products) and 1,3-oxazin-2-one derivatives (thermodynamically favored) from easily accessible allenic carbamates has been carried out. Keywords: allenes; computational chemistry; gold; gold catalysis; heterocycles; reaction

• mechanisms; Introduction The search for new synthetic routes to 1,3-oxazin-2-one derivatives [1] is of interest because of the biological activity of these molecules [2][3][4][5][6][7]. Carretero and colleagues have published the Au(I)-catalyzed cyclization of N-Boc-3-butyn-1-amines to afford six-membered 2

Complete σ* intramolecular aromatic hydroxylation mechanism through O₂ activation by a Schiff base macrocyclic dicopper(I) complex

• Albert Poater and
• Miquel Solà

Beilstein J. Org. Chem. 2013, 9, 585–593, doi:10.3762/bjoc.9.63

• . Finally, comparison of the reaction mechanisms involving hexaazamacrocyclic bsH2m and H3m ligands indicates that the energy barriers present in the H3m reaction mechanism are somewhat lower than those found in the more rigid bsH2m ligand. Stationary points located along the reaction path of the aromatic

Some aspects of radical chemistry in the assembly of complex molecular architectures

• Béatrice Quiclet-Sire and
• Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

• over the years. Our research is curiosity driven, guided by a search for novelty and a thirst for understanding reaction mechanisms. Constructing complex molecular architectures is only incidental to our work, mostly a consequence of our exploration of the scope and limitations of our methods. The

Electron and hydrogen self-exchange of free radicals of sterically hindered tertiary aliphatic amines investigated by photo-CIDNP

• Martin Goez,
• Isabell Frisch and
• Ingo Sartorius

Beilstein J. Org. Chem. 2013, 9, 437–446, doi:10.3762/bjoc.9.46

• observed [8][9]. One of the most versatile methods to elucidate complex reaction mechanisms that occur via paramagnetic intermediates is provided by measurements of chemically induced dynamic nuclear polarization (CIDNP) [10][11][12][13][14][15]. CIDNP arises from a spin-sorting process in radical pairs

• spectroscopy attaches labels (the polarizations) at the stage of the intermediates and observes them in the products, thus highlighting the interconnections of species along the reaction coordinate. The present study thus again demonstrates the power of CIDNP to provide detailed insights into complex reaction

• mechanisms. Experimental TIPA was synthesized and purified according to a literature procedure [47]; DABCO and all the sensitizers were commercially obtained and purified by double sublimation. The purchased solvent acetonitrile-d3 was carefully dried to a water content of less than 5 × 10−4 M in a specially

Recent advances in transition-metal-catalyzed intermolecular carbomagnesiation and carbozincation

• Kei Murakami and
• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 278–302, doi:10.3762/bjoc.9.34

• phenylmagnesium reagent provided 3i whereas the reaction with a vinylmagnesium reagent gave 3j. The reaction mechanisms are shown in Scheme 25. They proposed that the carbon–carbon bond cleavage happened prior to the carbometalation reactions, which is different from other ring-opening reactions of cyclopropenes

A chemist and biologist talk to each other about caged neurotransmitters

• Graham C.R. Ellis-Davies

Beilstein J. Org. Chem. 2013, 9, 64–73, doi:10.3762/bjoc.9.8

• practical purposes we make stock solutions for freezing in aliquots, and only thaw for use at the desired time. Chemist: Since 1980, the rate of release of the caged compound has been the subject of study by those who develop caged compounds [3]. Since the reaction mechanisms are quite complex, these

• rate of release of product is the key property [3][62][63]. In fact this is one reason why chemists study reaction mechanisms, as there can be several intermediates along the reaction pathway, leading to transmitter release [73]. Unfortunately, there is no easy way to detect glutamate optically, so the

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Discovery of practical production processes for arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides): Beginning of a new era of “super-trifluoromethyl” arene chemistry and its industry

• Teruo Umemoto,
• Lloyd M. Garrick and
• Norimichi Saito

Beilstein J. Org. Chem. 2012, 8, 461–471, doi:10.3762/bjoc.8.53

• these new reactions are revealed and reaction mechanisms are discussed. As the method offers considerable improvement over previous methods in cost, yield, practicality, applicability, and large-scale production, the new processes described here can be employed as the first practical methods for the

Alkene selenenylation: A comprehensive analysis of relative reactivities, stereochemistry and asymmetric induction, and their comparisons with sulfenylation

• Vadim A. Soloshonok and
• Donna J. Nelson

Beilstein J. Org. Chem. 2011, 7, 744–758, doi:10.3762/bjoc.7.85

• demonstrated that such different data point groupings reflect different steric and electronic characteristics of the rate-determining transition states, intermediates, or products. These different patterns have corresponded to different reaction mechanisms [72][73][74][75][76][77][78]. Thus, the different

The arene–alkene photocycloaddition

• Ursula Streit and
• Christian G. Bochet

Beilstein J. Org. Chem. 2011, 7, 525–542, doi:10.3762/bjoc.7.61

• yields up to 94% of the para photocycloaddition product, while other substituents gave yields of up to 44% of the benzoxepine compound. Pericyclic reaction mechanisms for these two photocycloadditions have been proposed, but no hard evidence has so far been obtained. The mechanism of this unprecedented

• step. We have discussed the diverse selectivities of the reaction, mechanisms as well as further modifications, and some of the most recent applications in total synthesis. Thus, while meta photocycloadditions have been exploited for over thirty years, ortho and, in particular, para photocycloadditions

A stable enol from a 6-substituted benzanthrone and its unexpected behaviour under acidic conditions

• Marc Debeaux,
• Kai Brandhorst,
• Peter G. Jones,
• Henning Hopf,
• Jörg Grunenberg,
• Wolfgang Kowalsky and
• Hans-Hermann Johannes

Beilstein J. Org. Chem. 2009, 5, No. 31, doi:10.3762/bjoc.5.31

• abstract hydride from another molecule that itself forms a stable cation (Scheme 5). In order to make the above mechanistic speculations more than simple “electron pushing”, we decided to apply the following computational methods. Reaction mechanisms by computational methods The gas phase global minima of