The details of the first nickel-catalyzed olefination of cyclic dithioacetals to form substituted styrenes and aryl-substituted 1,4-pentadienes are described. The reaction represents a new synthetic use of the dithioacetal functionality. Only nickel complexes catalyzed these cross-coupling reactions; palladium complexes displayed no catalytic activity under the reaction conditions employed. Selective coupling occurred. A mechanism for the reaction is proposed. The experimental evidence indicates that, in these nickel-catalyzed couplings, cyclic dithioacetals are more reactive than their acyclic analogues. This increased reactivity appears to be the result of maintaining the two sulfur atoms in close proximity to each other by the use of a short chain of methylene groups.
COMPOUNDS HAVING FUNGICIDAL ACTIVITY AND PROCESSES TO MAKE AND USE SAME
申请人:Dow AgroSciences LLC
公开号:EP1341534B1
公开(公告)日:2010-03-31
ORGANIC LIGHT-EMITTING DIODES WITH FLUORESCENT AND PHOSPHORESCENT EMITTERS
申请人:ARIZONA BOARD OF REGENTS ON BEHALF OF ARIZONA STATE UNIVERSITY
公开号:US20220238833A1
公开(公告)日:2022-07-28
A light emitting device includes a first electrode, a hole transporting layer in contact with the first electrode, a second electrode, an electron transporting layer in contact with the second electrode; and an emissive layer between the hole transporting layer and the electron transporting layer. The emissive layer includes a phosphorescent emitter, a fluorescent emitter, and a host, and the phosphorescent emitter harvests electrogenerated excitons and transfers energy to the fluorescent emitter.
Represented herein is a simple thiol identified as an effective precursor to photochemically form a carbocation. Thanks to the thiyl radical rapid transformation to disulfide, which serves not only to stabilize the generated thiyl radical but also to allow the second electron transfer to form a carbocation. The resulting carbocations, including primary benzylic, secondary, and tertiary carbocations