The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts

• Kari Raatikainen,
• Massimo Cametti and
• Kari Rissanen

Beilstein J. Org. Chem. 2010, 6, No. 4, doi:10.3762/bjoc.6.4

• nucleophilic substitution reaction of 3-iodopyridine with (chloromethyl)benzene (the synthesic details will be reported elsewhere). Slow evaporation of a moist ethanol solution gave an X-ray-quality crystal of 9. The asymmetric unit contains two molecules of N-benzyl-3-iodopyridinium chloride, a water molecule

The vicinal difluoro motif: The synthesis and conformation of erythro- and threo- diastereoisomers of 1,2-difluorodiphenylethanes, 2,3-difluorosuccinic acids and their derivatives

• David O'Hagan,
• Henry S. Rzepa,
• Martin Schüler and
• Alexandra M. Z. Slawin

Beilstein J. Org. Chem. 2006, 2, No. 19, doi:10.1186/1860-5397-2-19

• acetonitrile in the dark. Under these conditions, the substitution proceeds smoothly to erythro-13 but only in 56% de indicating a significant loss of stereochemical control during the reaction. The predominant stereochemical outcome of the fluorine substitution reaction suggests a double inversion mechanism

EcoScale, a semi- quantitative tool to select an organic preparation based on economical and ecological parameters

• Koen Van Aken,
• Lucjan Strekowski and
• Luc Patiny

Beilstein J. Org. Chem. 2006, 2, No. 3, doi:10.1186/1860-5397-2-3

• involved. It takes into account the amount of the reagents incorporated into the end product. Cycloadditions are examples of transformations with 100% atom economy. For other reactions (e.g. substitution reaction), a 100 % economy can never be reached due to the intrinsic nature of the reaction. The main

New modification of the Perkow reaction: halocarboxylate anions as leaving groups in 3-acyloxyquinoline- 2,4(1H,3H)-dione compounds

• Oldřich Paleta,
• Karel Pomeisl,
• Stanislav Kafka,
• Antonín Klásek and
• Vladislav Kubelka

Beilstein J. Org. Chem. 2005, 1, No. 17, doi:10.1186/1860-5397-1-17

• out[3] (product 2) via the intramolecular Wittig synthesis using a bromoacetyl derivative of the starting 3-hydroxyquinolinediones (1, Scheme 1). Unlike haloalkanes and halocycloalkanes that undergo nucleophilic substitution reaction with trialkyl phosphites to afford the corresponding phosphonates

Methods for the synthesis of polyhydroxylated piperidines by diastereoselective dihydroxylation: Exploitation in the two-directional synthesis of aza-C-linked disaccharide derivatives

• Andrew Kennedy,
• Adam Nelson and
• Alexis Perry

Beilstein J. Org. Chem. 2005, 1, No. 2, doi:10.1186/1860-5397-1-2

• structural complexity had been introduced as a consequence of the two-directional nature of the approach (sulfonamide oxidation, two oxidative ring expansions, two protection reactions and one N,O acetal substitution reaction). The stage was set for two-directional functionalisation of the heterocyclic rings