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

• agreement between experimental and calculated values of ∆G‡298. Keywords: amines; CIDNP; electron transfer; free radicals; hydrogen transfer; ketones; kinetics; photochemistry; self-exchange; Introduction Sensitized hydrogen abstractions from tertiary aliphatic amines present a mechanistic spectrum with a

• , which leads to opposite polarizations in the products of the two radicals of a pair with each other (geminate products) and the products of subsequent free radicals (escape products), and thus yields information about the entry and exit channels of the radical pairs. The spin sorting is driven by

• pulsed laser triggers a photoreaction; after a short delay, the polarizations of the products are probed with an NMR pulse; variation of the delay yields the kinetics. The method is very well suited to study bimolecular reactions of the free radicals, because typical NMR pulses are of microsecond

Bioactive selaginellins from Selaginella tamariscina (Beauv.) Spring

• Chao Yang,
• Yutian Shao,
• Kang Li and
• Wujiong Xia

Beilstein J. Org. Chem. 2012, 8, 1884–1889, doi:10.3762/bjoc.8.217

• diseases. The role of free radicals in ageing, in cancer, and in cardiovascular, neurodegenerative and other diseases is more and more widely accepted [21][22]. Antioxidants are attracting increasing scientific and clinical attention. Natural phenolic compounds (flavonoids, lignans, phenolic acids

EPR and pulsed ENDOR study of intermediates from reactions of aromatic azides with group 13 metal trichlorides

• Giorgio Bencivenni,
• Riccardo Cesari,
• Daniele Nanni,
• Hassane El Mkami and
• John C. Walton

Beilstein J. Org. Chem. 2010, 6, 713–725, doi:10.3762/bjoc.6.84

• with group 13 metal trichlorides Acknowledgements We thank EaStChem and the EPSRC (UK Basic Technology Programme grant GR/S85726/01) for financial assistance. We also acknowledge financial support from MIUR, Italy (2008 PRIN funds for ‘Properties and reactivity of free radicals in complex environments

Synthesis of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide – a tailor-made photoinitiator for dental adhesives

• Norbert Moszner,
• Iris Lamparth,
• Jörg Angermann,
• Urs Karl Fischer,
• Frank Zeuner,
• Thorsten Bock,
• Robert Liska and
• Volker Rheinberger

Beilstein J. Org. Chem. 2010, 6, No. 26, doi:10.3762/bjoc.6.26

• between ~360 and 400 nm can be generally assigned to symmetry forbidden n-π* transitions, which are responsible for α-cleavage and formation of free radicals [17]. After excitation with light in the near UV–vis, the excited triplet state undergoes cleavage of the carbon-phosphorus bond, thereby producing