Synthesis ofC3-Symmetric Nano-Sized Polyaromatic Compounds by Trimerization and Suzuki−Miyaura Cross-Coupling Reactions
作者:Sambasivarao Kotha、Dhurke Kashinath、Kakali Lahiri、Raghavan B. Sunoj
DOI:10.1002/ejoc.200400257
日期:2004.10
Various C3-symmetric molecules were prepared by trimerization of acetyl aromatic compounds and subsequently coupled with various boronic acids under Pd0 catalysis conditions to generate oligoaryl/-heteroaryl C3-symmetric molecules. Several furan- and thiophene-containing star-shaped molecules were prepared by the use of Suzuki−Miyauracross-coupling as a key step. Structural and conformational details
Isoxazole derivatives, and their use in liquid-crystalline mixtures
申请人:Clariant International Ltd.
公开号:US06616989B1
公开(公告)日:2003-09-09
Isoxazole derivatives of the formula (I)
where the symbols and indices have the following meanings, for example:
T is
X is S or O
R1 and R2 are identical or different and are each hydrogen, F, CN or a straight-chain or branched C1-C20-alkyl or C2-C20-alkenyl radical (with or without asymmetric carbon atoms),
A1 and A2 are undirected and identical or different and are each phenylene-1,4-diyl,
M1 is undirected and is —OC(═O)—, —OCH2—, —SC(═O)—, —SCH2—, —CH2CH2—, —OC(═O)CH2CH2—, —OCH2CH2CH2—, —C≡C—, —(CH2)4— or a single bond;
a is 0 or 1,
are used in liquid-crystal mixtures.
The present invention provides a process for producing a 2-acylthiophene compound which has a low content of the 3-isomer generated as a by-product, the process comprising reacting a thiophene compound represented by formula (1):
wherein R
1
is a hydrogen atom, a C
1-6
alkyl group, a phenyl group, or a halogen atom, with at least one member selected from the group consisting of acid anhydrides represented by formula (2):
wherein R
2
is a C
1-6
alkyl group or a phenyl group, and acid halides represented by formula (3):
wherein R
2
is as defined above and X is a halogen atom, in the presence of a solid acid catalyst at a temperature less than 75° C. in the absence of solvent, thus producing a 2-acylthiophene compound represented by formula (4):
wherein R
1
and R
2
are as defined above.
Disclosed are compounds having the formula:
wherein X
1
, X
2
, X
3
, R
1
, R
2
, Y, Q, X, B and L are as defined herein, and methods of making and using the same.
The present invention provides a process for producing a 2-acylthiophene compound which has a low content of the 3-isomer generated as a by-product, the process comprising reacting a thiophene compound represented by formula (1) :
wherein R1 is a hydrogen atom, a C1-6 alkyl group, a phenyl group, or a halogen atom, with at least one member selected from the group consisting of acid anhydrides represented by formula (2):
wherein R2 is a C1-6 alkyl group or a phenyl group, and
acid halides represented by formula (3):
wherein R2 is as defined above and X is a halogen atom,
in the presence of a solid acid catalyst at a temperature less than 75°C in the absence of solvent, thus producing a 2-acylthiophene compound represented by formula (4):
wherein R1 and R2 are as defined above.