Liquid–crystalline perylene tetracarboxylic acid bisimide bearing oligosiloxane chains with high electron mobility and solubility
摘要:
Liquid-crystalline perylene tetracarboxylic acid bisimide derivatives 1 and 2 bearing 1,1,1,2,2,3,3-heptamethyltrisiloxane chains at the end of alkyl side-chains have been synthesized. Compound 1 having four trisiloxane chains exhibits a hexagonal columnar phase at room temperature. Time-of-flight measurement reveals that the electron mobility in the columnar phase of compound 1 exceeds 10 (3) cm(2) V (1) s (1) at room temperature. In contrast, compound 2 bearing two trisiloxane chains is not mesomorphic. These two compounds are soluble in various organic solvents except for alcohols and thin films can be produced by a spin-coating method. (C) 2012 Elsevier B. V. All rights reserved.
Diverse<i>N</i>-Heterocyclic Ring Systems via Aza-Heck Cyclizations of<i>N</i>-(Pentafluorobenzoyloxy)sulfonamides
作者:Ian R. Hazelden、Xiaofeng Ma、Thomas Langer、John F. Bower
DOI:10.1002/anie.201605152
日期:2016.9.5
bond of N‐(pentafluoro‐benzoyloxy)sulfonamides are described. These studies, which encompass only the second class of aza‐Heck reaction developed to date, provide direct access to diverse N‐heterocyclicringsystems.
作者:Annabella F. Newton、Stephen J. Roe、Jean-Christophe Legeay、Pooja Aggarwal、Camille Gignoux、Nicola J. Birch、Robert Nixon、Marie-Lyne Alcaraz、Robert A. Stockman
DOI:10.1039/b907720k
日期:——
Two-directional cross-metathesis of a range of α,ω dienes with a variety of electron deficient alkenes has been accomplished. It was found that the process is quite general and gives complete selectivity for the E,E-dienes, making this a very useful and high yielding protocol for two-directional chain elongation.
Increased Yields and Simplified Purification with a Second-Generation Cobalt Catalyst for the Oxidative Formation of <i>trans</i>-THF Rings
作者:Cory Palmer、Nicholas A. Morra、Andrew C. Stevens、Barbora Bajtos、Ben P. Machin、Brian L. Pagenkopf
DOI:10.1021/ol9023375
日期:2009.12.17
The synthesis of a second-generation cobalt catalyst for the formation of trans-THF products via the Mukaiyama aerobic oxidative cyclization is reported. Two procedures have been developed with the new water-soluble catalyst that give superior yields and greatly simplify purification compared to the previous catalysts.
Spiroacetal Biosynthesis: (±)-1,7-Dioxaspiro[5.5]undecane in <i>Bactrocera </i><i>c</i><i>acuminata</i> and <i>Bactrocera</i> <i>o</i><i>leae</i> (Olive Fruit Fly)
作者:Brett D. Schwartz、Christopher S. P. McErlean、Mary T. Fletcher、Basilis E. Mazomenos、Maria A. Konstantopoulou、William Kitching、James J. De Voss
DOI:10.1021/ol050143w
日期:2005.3.1
rationalizing the formation of (+/-)-1,7-dioxaspiro[5.5]undecane (5) in the fruit fly species Bactrocera cacuminata and Bactrocera oleae (olive fruit fly) is presented. Incorporation studies with deuterium-labeled keto aldehyde (10), 1,5-nonanediol (11), and 1,5,9-nonanetriol (12), and our previous finding that both oxygen atoms of 5 originate from dioxygen, are strongly evidentiary. The racemic condition
Intermolecularhydroacylation between salicylaldehydes 1, 26−40 and 1,4-penta- or 1,5-hexadienes 4−13 by Rh-catalyst proceeded under mild reaction conditions to give a mixture of iso- and normal-hydroacylated products 14−25, 41−55, and 57−60. In the hydroacylationreaction, chelation of both salicylaldehyde and diene to the Rh-complex plays a crucial role. The ratio of iso- and normal-hydroacylated