- Arylzinc species by microwave assisted Grignard formation-transmetallation sequence: Application in the Negishi coupling
-
Arylmagnesium species can be efficiently generated from magnesium turnings and aryl chlorides or aryl bromides under dielectric heating conditions. Subsequent microwave assisted transmetallation using ZnCl2-TMEDA afforded the corresponding arylzinc reagents. A sequential microwave assisted arylmagnesium formation-transmetallation-Negishi coupling protocol suitable for automated multiple parallel synthesis has been developed.
- Mutule, Ilga,Suna, Edgars
-
-
Read Online
- Preparation method for bis[di-tert-butyl(4-dimethylaminophenyl)phosphine]dichloropalladium
-
The invention discloses a preparation method for bis[di-tert-butyl(4-dimethylaminophenyl)phosphine]dichloropalladium. The preparation method comprises the following steps that 1, a Grignard reagent isprepared from the raw materials of N, N-dimethyl p-haloaniline and magnesium chips; 2, the Grignard reagent is taken and cooled, then a catalyst is added for reaction, then di-tert-butylchlorophosphane is dropwise added, and heating is carried out for reaction so as to obtain di-tert-butyl-4-dimethylaminophenylphosphine; 3, the di-tert-butyl-4-dimethylaminophenylphosphine is purified; and 4, complexing bis(acetonitrile)dichloropalladium and the purified di-tert-butyl-4-dimethylaminophenylphosphine so as to obtain a target product. The preparation method has the advantages that the di-tert-butyl-4-dimethylaminophenylphosphine is purified, the high-purity di-tert-butyl-4-dimethylaminophenylphosphine is used for reacting with the bis(acetonitrile)dichloropalladium, and therefore the yield loss of the noble metal palladium is greatly reduced, the preparation cost is greatly lowered, and the method has a good practical value.
- -
-
Paragraph 0057; 0058
(2018/11/03)
-
- Regioselective 1,4-conjugate addition of grignard reagents to nitrodienes in the presence of catalytic amounts of Zn(II) salts
-
Grignard reagents undergo facile regioselective 1,4-conjugate addition to nitrodienes in the presence of catalytic amounts of Zn(II) salts with excellent yields. A wide range of ligands such as alkyl, aryl, heteroaryl, allyl, vinyl, 1-alkynyl, and alkoxy ligands were transferred, while a thiolate ligand afforded 1,6-regioselectivity. The reactions were successfully carried out on δ-alkyl- or aryl-substituted α,β,γ,δ-diunsaturated nitrodiene substrates. Regioselectivity is minimally influenced by temperature or choice of solvent.
- Dhakal, Ramesh C.,Dieter, R. Karl
-
supporting information
p. 1362 - 1365
(2014/04/03)
-