Effects of anion complexation on the photoreactivity of bisureido- and bisthioureido-substituted dibenzobarrelene derivatives

• Heiko Ihmels and
• Jia Luo

Beilstein J. Org. Chem. 2011, 7, 278–289, doi:10.3762/bjoc.7.37

• formation of the dibenzosemibullvalene with moderate stereoselectivity (68:32 er). In contrast, the thioureido derivative showed no such effect upon complexation of chiral anions. Keywords: dibenzobarrelenes; dibenzosemibullvalenes; di-π-methane rearrangement; supramolecular photochemistry; (thio)urea

• challenge to develop a method to accomplish stereoselective DPM rearrangements of dibenzobarrelene derivatives in homogenous solutions. Therefore, we intended to study whether supramolecular interactions of chiral additives with achiral dibenzobarrelenes may be used to influence the photoreactivity of the

• . Structures of chiral additives employed in DPM rearrangements. Structure of anthracene–thiourea conjugate 4. Proposed structure of the complex between 1h and mandelate SMD. Photorearrangements of dibenzobarrelenes 1a and 1b. Stereoselective DPM rearrangement of chiral salts in the solid-state. Synthesis of

Synthesis of cationic dibenzosemibullvalene-based phase-transfer catalysts by di-π-methane rearrangements of pyrrolinium-annelated dibenzobarrelene derivatives

• Heiko Ihmels and
• Jia Luo

Beilstein J. Org. Chem. 2011, 7, 119–126, doi:10.3762/bjoc.7.17

• pyrrolidinium-annelated dibenzosemibullvalene may act as phase-transfer catalyst in alkylation reactions. Keywords: di-π-methane rearrangement; dibenzobarrelenes; dibenzosemibullvalenes; phase-transfer catalysis; photochemistry; polycylic compounds; Introduction The di-π-methane (DPM) rearrangement is among