Reversible intramolecular photocycloaddition of a bis(9-anthrylbutadienyl)paracyclophane – an inverse photochromic system. (Photoactive cyclophanes 5)

• Henning Hopf,
• Christian Beck,
• Jean-Pierre Desvergne,
• Henri Bouas-Laurent,
• Peter G. Jones and
• Ludger Ernst

Beilstein J. Org. Chem. 2009, 5, No. 20, doi:10.3762/bjoc.5.20

• recovered by irradiation at 306 nm or by heating. This ‘inverse’ photochromic system has a potential for optical information storage, compound 4 being stable in visible light, at ambient temperature. Keywords: anthracenes; cyclophanes; inverse photochromism; photocycloaddition; Introduction Photochromism

• carbons (54.9 to 66.0 ppm) and finally 4 to CH2 (31.6 to 36.5 ppm), attributable to the ethanocyclophane bridges. In previously studied cyclophanes, the cyclobutane rings exhibited 13C signals between 42 and 51 ppm [18][19]. No such signals are apparent in the present case; therefore it is proposed that

Synthesis of dihydrophenanthridines by a sequence of Ugi-4CR and palladium- catalyzed intramolecular C-H functionalization

• Florence Bonnaterre,
• Michèle Bois-Choussy and
• Jieping Zhu

Beilstein J. Org. Chem. 2008, 4, No. 10, doi:10.3762/bjoc.4.10

• developed two-step syntheses of a number of macrocycles including cyclophanes and cyclodepsipeptides [7][8][9][10]. We have also reported the elaboration of Ugi-adduct containing two arylhalide functions for the synthesis of 1,4-benzodiazepine-2,5-diones [11] and their tetracyclic derivatives [12] featuring