Search results
Search for "halogen bond" in Full Text gives 30 result(s) in Beilstein Journal of Organic Chemistry.
New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation
Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283
- organic catalysts for electrophile activation through the formation of C–H hydrogen bonds and C–X halogen bonds. Keywords: C–H hydrogen bond; counteranion activation; electrophile activation; halogen bond donor; hydrogen bond donor; organocatalysis; Review Introduction Over the past century chemists
- form stable adducts with neutral and charged Lewis bases, and to account for this IUPAC provided the following recommendation “A halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a
- and are critical for the resolution. This example clearly demonstrate the great potential of halogen bonds as tools for asymmetric catalysis. Early uses of halogen bond donors in catalysis and organocatalysis Like hydrogen bonds, halogen bonds possess important features such as strength and
Trifluoromethyl-substituted tetrathiafulvalenes
Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73
- accordingly, several tetrathiafulvalenes bearing only one or two ester [10], nitrile [11][12][13][14], amide [7][15][16][17], thioamide [18][19][20], or halogen [5] substituents were successfully engaged in radical cation salts by electrocrystallization, with intermolecular hydrogen [21][22][23] of halogen
- bond interactions [24][25][26][27]. Within such TTF derivatives, as reported by Bryce [28], an internal charge transfer (ICT) between the TTF and the EWG moieties increases the hydrophilicity of the TTF head groups and facilitates monolayer formation on the water surface for the preparation of Langmuir
Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes
Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198
- moderate yields, this strategy constitutes an alternative choice to the palladium-catalyzed cyclization of indole amides bearing a carbon–halogen bond to give medium and large ring-fused indoles [72]. Although a stoichiometric amount of Pd(OAc)2 is needed, intramolecular alkenylations of suitable 3
Kinetic evaluation of the solvolysis of isobutyl chloro- and chlorothioformate esters
Beilstein J. Org. Chem. 2011, 7, 543–552, doi:10.3762/bjoc.7.62
- to the chlorocarbonyl group in alkyl chloro- and chlorothioformates, the positive entropies and low solvent isotope effects pointed to a mechanism involving a unimolecular acyl–halogen bond fission. More recent studies on alkyl and aryl chlorothio-, chlorodithio-, and chlorothionoformate esters favor
The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts
Beilstein J. Org. Chem. 2010, 6, No. 4, doi:10.3762/bjoc.6.4
- systems and its potential in drug development has also been recognized [22]. The halogen bond (XB), whose terminology emphasizes the similarity with hydrogen bonding [23] can be schematically described by Y–X···A, where X is the XB donor atom (Lewis acid, electrophilic) and A is the XB acceptor atom
- ], following the polarizability of halogen atom. The hybridization of the C–X carbon atom on the XB donor molecule has also an effect on the strength and directionality of the halogen bond. The order C(sp3) < C(sp2) < C(sp) is generally followed [24][25][26] and for example haloalkynes are found to be
- particularly good halogen bond donors [27][28]. As seen in PFC compounds, electron withdrawing moieties present on the Y group favor the interaction. For this reason haloarenes where the aromatic ring has electron withdrawing substituents e.g. fluorines [11][12][13][14][15][16][18][19] are also excellent
Other Beilstein-Institut Open Science Activities
