90822-65-4Relevant academic research and scientific papers
Nickel-catalyzed cycloaddition of 1,3-dienes with 3-azetidinones and 3-oxetanones
Thakur, Ashish,Facer, Megan E.,Louie, Janis
, p. 12161 - 12165 (2013)
A growth and expansion strategy: A Ni/P(p-tol)3-catalyzed cycloaddition of 1,3-dienes with 3-azetidinones and 3-oxetanones produced eight-membered heterocycles with a variety of substituents (see scheme; Boc=tert-butoxycarbonyl). The synthesis of the reduced azocine and oxocine derivatives involved the challenging steps of C(sp2)-C(sp 3) bond activation and C(sp3)-C(sp3) reductive elimination. Copyright
Pd-catalyzed cross-coupling reactions of hydrazones: Regioselective synthesis of highly branched dienes
Ojha, Devi Prasan,Prabhu, Kandikere Ramaiah
, p. 12136 - 12143 (2014/01/06)
The regioselective formation of highly branched dienes is a challenging task. Design and exploration of alternative working models to achieve such a regioselectivity to accomplish highly branched dienes is considered to be a historical advancement of Heck reaction to construct branched dienes. On the basis of the utility of carbene transfer reactions, in the reaction of hydrazones with Pd(II) under oxidative conditions, we envisioned obtaining a Pd-bis-carbene complex with α-hydrogens, which can lead to branched dienes. Herein, we report a novel Pd-catalyzed selective coupling reaction of hydrazones in the presence of t-BuOLi and benzoquinone to form the corresponding branched dienes. The utility of the Pd catalyst for the cross-coupling reactions for synthesizing branched conjugated dienes is rare. The reaction is very versatile and compatible with a variety of functional groups and is useful in synthesizing heterocyclic molecules. We anticipate that this Pd-catalyzed cross-coupling reaction will open new avenues for synthesizing useful compounds.
Reactions of 2,3-Dimethylenebutadiene Dianion with Electrophiles. Synthesis and Conformations of 2,3-Disubstituted-1,3-butadienes
Bates, Robert B.,Gordon, Bernard,Highsmith, Thomas K.,White, James J.
, p. 2981 - 2987 (2007/10/02)
Reactions of 2,3-dimethylenebutadiene dianion 1 with monofunctional electrophiles were found to provide the best routes to symmetrically substituted 1,3-butadienes such as 2c - n.Evidence that at least some of these reactions go by single electron-transfer mechanisms is presented.Possible mechanisms for the formation of some unusual byproducts are discussed.Reactions of 1 with dichlorides and dibromides were found to provide the best routes to most 1,2-dimethylenecycloalkanes 3, the corresponding dimers 4 and trimers 5, and 1,1-dimethyl-3,4-dimethylene-1-metallacyclopentanes 26.From their UV spectra, the dienes 2 contain about 60percent transoid conformations, except 2,3-dimethyl-1,3-butadiene (2a) which shows about 100percent and 2,3-dineopentyl-1,3-butadiene (2h) which shows about 30percent. 1,2-Dimethylenecycloalkanes 3 display cisoid conformations in rings smaller than 9-membered and transoid conformations in rings larger than 11.When the ring size exceeds 15, the homoallylic methylene groups on both sides are also anti coplanar.With rings larger than about 30, the next methylene group on each side is also anti coplanar, and when the ring size exceeds about 45, an additional methylene on each side is anti coplanar.
