- 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)
-
- Cobalt-catalyzed addition of arylzinc reagents to alkynes to form ortho-alkenylarylzinc species through 1,4-cobalt migration
-
Migratory carbometalation: A cobalt-Xantphos complex catalyzes the addition of an arylzinc reagent to an unactivated internal alkyne; the reaction most likely involves insertion of the alkyne into an arylcobalt species and vinyl-to-aryl 1,4-cobalt migration, followed by transmetalation with the arylzinc reagent. Interception of the resulting ortho-alkenylarylzinc species with electrophiles allows access to 1-alkenyl arenes functionalized in the 2-position. Copyright
- Tan, Boon-Hong,Dong, Jinghua,Yoshikai, Naohiko
-
supporting information
p. 9610 - 9614
(2012/11/07)
-
- 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
-
p. 11168 - 11176
(2007/10/03)
-