Palladium-Catalyzed C–H Arylation of (Benzo)oxazoles or (Benzo)thiazoles with Aryltrimethylammonium Triflates
摘要:
The C-H arylation of (benzo)oxazoles or (benzo)thiazoles with aryltrimethylammonium triflates was carried out via Pd-catalyzed C-H/C-N cleavage. Oxazoles, thiazoles, benzoxazole, and benzothiazole were arylated using activated and deactivated aryltrimethylamrnonium triflates to give 2-aryl(benzo)oxazoles or 2-aryl(benzo)thiazoles in reasonable to excellent yields.
Convenient One-Pot Synthesis of 2,5-Disubstituted Oxazoles via a Catalytic Oxidative Dehydrogenation of F<sub>3</sub>CSO<sub>3</sub>H·SiO<sub>2</sub>-DDQ/CuCl<sub>2</sub>/LiCl
作者:Shizhen Yuan、Zhen Li、Ling Xu
DOI:10.1002/jhet.1637
日期:2013.11
A facile one‐potsynthesis of 2,5‐disubstitutedoxazoles was developed via cyclization of aldoximes and phenylacetylene then dehydrogenation oxidation. 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone was studied for the selective oxidation of oxazolines using Cu2+/Li+ as catalyst and O2 as indirect oxidant. The reaction results showed that this catalyst system can effectively catalyze the oxidation of oxazolines
通过醛肟和苯乙炔的环化然后脱氢氧化制得了一种简便的一锅合成2,5-二取代的恶唑。以Cu 2+ / Li +为催化剂,O 2为间接氧化剂,研究了2,3-二氯-5,6-二氰基-1,4-苯醌对氧化唑啉的选择性氧化。反应结果表明,该催化剂体系可有效催化恶唑啉氧化为相应的恶唑。因此,通过2,3-二氯-5,6-二氰基-1,4-苯醌/ CuCl 2 / LiCl / O 2的催化氧化,很容易以高收率合成各种多取代的恶唑。
The versatile palladium complex Pd(PPh3)4 catalyses both direct arylation and alkenylation of oxazoles efficiently. The method is regioselective and stereospecific with respect to bromoalkenes and tolerates a wide range of functional groups.
Synthesis of Oxazoles through Copper-Mediated Aerobic Oxidative Dehydrogenative Annulation and Oxygenation of Aldehydes and Amines
作者:Zejun Xu、Chun Zhang、Ning Jiao
DOI:10.1002/anie.201206382
日期:2012.11.5
A fragment‐assembling strategy is used to form oxazoles from aryl acetaldehydes, amines, and molecular oxygen under mild conditions (see scheme). The transformation is highly efficient with the removal of six hydrogen atoms, including the cleavage of four C(sp3)H bonds.
Silylated polycarbonate polymers, method of making, and articles
申请人:Lens Jan Pleun
公开号:US20080306294A1
公开(公告)日:2008-12-11
A silylated dihydroxy aromatic compound of the formula (1a);
wherein G
a
and G
b
are each independently C
1-12
alkyl, —OSi(C
1-12
alkyl)
3
, C
1-12
arylalkyl, or —OSi(C
1-12
arylalkyl)
3
; Z
a
and Z
b
are each independently a straight or branched C
2-18
alkylene, a C
8-18
arylalkylene, or a C
8-18
alkylarylene, X
a
is a direct bond, a heteroatom-containing group, or a C
1-18
organic group, and r and s are each independently 1 or 2 is disclosed.