Valence isomerization of cyclohepta-1,3,5-triene and its heteroelement analogues

• Helen Jansen,
• J. Chris Slootweg and
• Koop Lammertsma

Beilstein J. Org. Chem. 2011, 7, 1713–1721, doi:10.3762/bjoc.7.201

• Helen Jansen J. Chris Slootweg Koop Lammertsma Department of Chemistry and Pharmaceutical Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands 10.3762/bjoc.7.201 Abstract The valence isomerization of the all-carbon and heteroelement analogues of cyclohepta

• necessitates a brief overview of the parent all-carbon system. This section is followed by one in which experimental data on the oxepine, thiepine, 1H-azepine, and 1H-phosphepine valence isomerizations are compared with those obtained by theoretical calculations. Computational methods have the advantage that

• -oxabicyclo[2.3.0]hepta-3,6-diene (13) [38][51], while under thermal, photochemical or acidic conditions, the three-membered ring of bicyclic 4 opens, generating phenol [67][68], in analogy to the all-carbon norcaradiene (2), which gives toluene. In addition, 4 undergoes highly selective Diels–Alder reactions

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

• authors proposed that these intermediates formally behave as an all-carbon 1,4-dipole that intermolecularly reacts with the indole providing the final polycyclic furan adducts 9 in a regioselective fashion (Scheme 4) [46]. In 2009, J. Zhang reported a gold(I)-catalyzed tandem cyclization/(3 + 3

Metathesis access to monocyclic iminocyclitol-based therapeutic agents

• Ileana Dragutan,
• Valerian Dragutan,
• Carmen Mitan,
• Hermanus C.M. Vosloo,
• Lionel Delaude and
• Albert Demonceau

Beilstein J. Org. Chem. 2011, 7, 699–716, doi:10.3762/bjoc.7.81

• iminocyclitols is dictated by the stereochemistry at all carbon atoms of the pyrrolidine ring system which can adopt either a manno or a galacto conformation, therefore inhibiting either α-mannosidases (e.g., 11–13) or α-galactosidases (e.g., 14) (Scheme 2). A characteristic feature in 11–14 is the presence of a

Palladium-catalyzed formation of oxazolidinones from biscarbamates: a mechanistic study

• Benan Kilbas and
• Metin Balci

Beilstein J. Org. Chem. 2011, 7, 246–253, doi:10.3762/bjoc.7.33

• of 6 [18]. Selective reduction of the peroxide linkage in 6 was carried out with thiourea under very mild conditions to give the diol 7 [19]. Since only the oxygen–oxygen bond is broken in this reaction, the configuration at all carbon atoms is preserved. Oxazolidinone 9 was synthesized by two

The allylic chalcogen effect in olefin metathesis

• Yuya A. Lin and
• Benjamin G. Davis

Beilstein J. Org. Chem. 2010, 6, 1219–1228, doi:10.3762/bjoc.6.140

• amino acids with allyl alcohol mediated by catalyst 4 was investigated. Unexpectedly, S-allylcysteine derivative 21a was the only substrate that afforded a synthetically useful amount of CM product, whereas the reaction of the all carbon analogue homoallylglycine (20) and sulfide derivatives, S-butenyl

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

• which saturated polyhydroxylated nitrogen and oxygen heterocycles are linked by an all-carbon tether. The saturated oxygen heterocycle has the potential to mimic the departing sugar in a glycosidase-catalysed reaction and aza-C-linked disaccharide mimetics may, therefore, be more potent inhibitors of