2013
DOI: 10.1002/adsc.201200629
|View full text |Cite
|
Sign up to set email alerts
|

Microwave‐Promoted Copper‐Free Sonogashira–Hagihara Couplings of Aryl Imidazolylsulfonates in Water

Abstract: Abstract. Aryl imidazol-1-ylsulfonates have been efficiently cross-coupled with aryl-, alkyl-, and silyl acetylenes in neat water under copper-free conditions at 110 ºC assisted by microwave irradiation. Using 0.5 mol% of an oxime palladacycle as precatalyst, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos, 2 mol%) as ligand, hexadecyltrimethylammonium bromide (CTAB) as additive, and triethylamine (TEA) as base, a wide array of disubstituted alkynes has been prepared in good to high yields in only 30 mi… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
1
1
1

Citation Types

0
22
0
1

Year Published

2013
2013
2022
2022

Publication Types

Select...
6
2

Relationship

3
5

Authors

Journals

citations
Cited by 38 publications
(23 citation statements)
references
References 34 publications
0
22
0
1
Order By: Relevance
“…67-7.62 (m, 4H), 7.59-7.57 (m, 2H), 7.42-7.39 (m, 3H); 13 C NMR (101 MHz, CDCl 3 ) δ(ppm): 132. 58, 132.57,132.51, 129.66, 129.04, 128.74, 122.72, 119.07, 111.96, 94.30, 88.26;FT-IR (KBr): 3413, 2929, 2822, 1634, 1440, 1390, 1375, 1098, 1050 1-chloro-4-(phenylethynyl)benzene (1f) 28 : White solid, m.p: 78-80 °C; 1 H NMR (400 MHz, CDCl 3 ) δ(ppm): 7. 58-56 (d, 2H, J= 8), 7.51-7.49 (d, 2H, J= 8), 7.42-7.39 (m, 2H), 7.39-7.35 (m, 3H); 13 C NMR (101 MHz, CDCl 3 ) δ(ppm): 134.…”
Section: A C C E P T E D Accepted Manuscriptmentioning
confidence: 99%
“…67-7.62 (m, 4H), 7.59-7.57 (m, 2H), 7.42-7.39 (m, 3H); 13 C NMR (101 MHz, CDCl 3 ) δ(ppm): 132. 58, 132.57,132.51, 129.66, 129.04, 128.74, 122.72, 119.07, 111.96, 94.30, 88.26;FT-IR (KBr): 3413, 2929, 2822, 1634, 1440, 1390, 1375, 1098, 1050 1-chloro-4-(phenylethynyl)benzene (1f) 28 : White solid, m.p: 78-80 °C; 1 H NMR (400 MHz, CDCl 3 ) δ(ppm): 7. 58-56 (d, 2H, J= 8), 7.51-7.49 (d, 2H, J= 8), 7.42-7.39 (m, 2H), 7.39-7.35 (m, 3H); 13 C NMR (101 MHz, CDCl 3 ) δ(ppm): 134.…”
Section: A C C E P T E D Accepted Manuscriptmentioning
confidence: 99%
“…As catalyst, oxime palladacycle 1a (1 mol% Pd) in the presence of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos, 2 mol%) was selected due to the high activity of this catalytic system for the alkynylation of aryl imidazolylsulfonates in water. [6,15] Unfortunately, under these conditions ( Table 1, entry 1), the reaction afforded 1-methyl-4-(phenylethynyl)benzene (4a) in a 14% isolated yield together with the enyne (E)-but-1-en-3-yne-1,4-diyldibenzene (5a) in a 7% yield. The formation of compound 5a has been previously detected in Heck alkynylations of deactivated aryl chlorides and it is postulated to occur via a Pd-catalyzed head-to-head dimerization of phenylacetylene.…”
Section: Resultsmentioning
confidence: 99%
“…[1] In organic synthesis, among the leading "name" Pd-catalyzed reactions, the Sonogashira-Hagihara coupling [2] is one of the most important and widely used methods for preparing aryl-and alkylacetylenes as well as conjugated enynes, which are precursors for natural products, pharmaceuticals, as well as optical and electronic materials. [2,3] Given the relevance of the Sonogashira reaction, the design of sustainable protocols to perform green aqueous couplings [4] is nowadays considered of high practical value, especially when deactivated electrophiles such as aryl chlorides [5] and hydroxyarene derivatives [6] are involved in the process. The use of water as a solvent in Pd-catalyzed reactions has gained increasing attention during last years [7] due to the environmental and economic benefits of replacing organic solvents by water as well as its interesting chemical properties, including high polarity and strong hydrogen-bonding ability, among others.…”
Section: Introductionmentioning
confidence: 99%
See 1 more Smart Citation
“…Since 1999, our lab has been involved in the development and use of oxime palladacycles 5 as highly active precatalysts for different cross-coupling reactions using organic and aqueous solvents. 6 Specifically, oxime palladacycles derived from 4,4'-dichlorobenzophenone 1a and 4-hydroxyacetophenone 1b have been shown to be very active precatalysts in the copper-free SonogashiraHagihara coupling of deactivated aryl bromides and chlorides 7 as well as aryl imidazolylsulfonates 8 with terminal alkynes in water under microwave irradiation. In continuation of our research on the application of oxime palladacycles in C-C coupling reactions under green conditions, herein we describe the stereo-and regioselective synthesis of (E)-head-to-head 1,4-diaryl-1,3-enynes via Pd-catalyzed dimerization of aryl alkynes in water assisted by microwave irradiation.…”
Section: Microwavementioning
confidence: 99%