p-CHOC(6)H(4)) undergo Suzuki-type three-component assembling with 1,1-dimethylallene to give the corresponding allylic derivatives, (CH(3))(2)=CRCH(2)Ar, in DMF at 70 degrees C in the presence of CsF using Pd(dba)(2) as the catalyst. Higher yields of products were obtained for aryliodides than for the corresponding aryl bromides and chlorides. This three-component assembling is highly regioselective
Palladium-Catalyzed Synthesis of 1,3-Dienes from Allenes and Organic Halides
作者:Hao-Ming Chang、Chien-Hong Cheng
DOI:10.1021/jo991651k
日期:2000.3.1
with aryl and vinylic halides to give diene products (3p-w). For 2d, both E and Z isomers 3t and 3u of the diene product were observed. For 2e, two regioisomers 3vand 3w were isolated with 3w likely from alkene isomerization of 3v. Various palladium systems were tested for the catalytic activity of diene formation. In addition to Pd(dba)(2)/PPh(3), Pd(OAc)(2)/PPh(3), PdCl(2)(PPh(3))(2), and PdCl(2)(dppe)
nickel(II) precatalysts for the preparation of 2-substituted 1,3-dienes by a Kumada cross-coupling between vinyl magnesium bromide and vinyl phosphates is described. This is noteworthy as engaging only one vinyl derivative in a transition-metal-catalyzed cross-coupling reaction is already reputedly challenging. Salient features of this method are its operational simplicity, the mild reaction conditions, the
Anion-Tuning of Organozincs Steering Cobalt-Catalyzed Radical Relay Couplings
作者:Xingchen Liu、Haohua Chen、Dali Yang、Binjing Hu、Ying Hu、Shengchun Wang、Yu Lan、Aiwen Lei、Jie Li
DOI:10.1021/acscatal.3c01763
日期:2023.7.7
with sulfonyl chlorides and OPiv-supported organozinc reagents was reported. Herein, anion-coordination played a critical role in the chemical property modification of organozinc reagents. Changing the anions of organozincs fromhalides (Cl, Br, and I) to pivalate (OPiv) resulted in a very different reactivity. OPiv-supported organozinc reagents steered the success of cobalt-catalyzed carbosulfonylation
π-Lewis basic palladium (0) catalysis, delivering benzofuran-fused eight-membered heterocycles in high efficiency, regio- and enantioselectivities. Highly diastereoselective derivatizations of the resultant eight-membered cyclic alkenes provide a facile access to diverse fused polycyclic compounds in excellent efficiency.