C-H Borylation/Cross-Coupling Forms Twisted Donor-Acceptor Compounds Exhibiting Donor-Dependent Delayed Emission.

Benzothiadiazole (BT) directed C-H borylation using BCl , followed by B-Cl hydrolysis and Suzuki-Miyaura cross-coupling enables facile access to twisted donor-acceptor compounds. A subsequent second C-H borylation step provides, on arylation of boron, access to borylated highly twisted D-A compounds with a reduced bandgap, or on B-Cl hydrolysis/cross-coupling to twisted D-A-D compounds. Photophysical studies revealed that in this series there is long lifetime emission only when the donor is triphenylamine.

Synthesis, Characterization, and Functionalization of 1-Boraphenalenes.

1-Boraphenalenes have been synthesized by reaction of BBr with 1-(aryl-ethynyl)naphthalenes, 1-ethynylnaphthalene, and 1-(pent-1-yn-1-yl)naphthalene and they can be selectively functionalized at boron or carbon to form bench-stable products. All of these 1-boraphenalenes have LUMOs localized on the planar C B core that are closely comparable in character to isoelectronic phenalenyl cations. In contrast to the comparable LUMOs, the aromatic stabilization of the C B ring in 1-boraphenalenes is dramatically lower than the C rings in phenalenyl cations.

Confirming the existence of π-allyl-palladium intermediates during the reaction of meta photocycloadducts with palladium(II) compounds.

The transient existence of π-allyl-palladium intermediates formed by the reaction of Pd(OAc)(2) and anisole-derived meta photocycloadducts has been demonstrated using NMR techniques. The intermediates tended to be short-lived and underwent rapid reductive elimination of palladium metal to form allylic acetates, however this degradation process could be delayed by changing the reaction solvent from acetonitrile to chloroform.

Investigating the arenyl-diene double [3 + 2] photocycloaddition reaction.

The double [3 + 2] photocycloaddition reaction involving arenyl-dienes has been used to assemble seven separate [5.5.5.