32960-45-5Relevant academic research and scientific papers
Enantioselective Nickel-Catalyzed Alkyne-Azide Cycloaddition by Dynamic Kinetic Resolution
Liu, En-Chih,Topczewski, Joseph J.
supporting information, p. 5308 - 5313 (2021/05/04)
The triazole heterocycle has been widely adopted as an isostere for the amide bond. Many native amides are α-chiral, being derived from amino acids. This makes α-N-chiral triazoles attractive building blocks. This report describes the first enantioselective triazole synthesis that proceeds via nickel-catalyzed alkyne-azide cycloaddition (NiAAC). This dynamic kinetic resolution is enabled by a spontaneous [3,3]-sigmatropic rearrangement of the allylic azide. The 1,4,5-trisubstituted triazole products, derived from internal alkynes, are complementary to those commonly obtained by the related CuAAC reaction. Initial mechanistic experiments indicate that the NiAAC reaction proceeds through a monometallic Ni complex, which is distinct from the CuAAC manifold.
Nickel-catalyzed Heck reaction of cycloalkenes using aryl sulfonates and pivalates
Zhou, Jianrong Steve,Huang, Xiaolei,Teng, Shenghan,Chi, Yonggui Robin
supporting information, p. 3933 - 3936 (2021/04/26)
Nickel-catalyzed Heck reaction of cycloalkenes delivers unusual conjugated arylated isomers. Nickel(0) catalysts ligated by chelating dialkylphosphines effectively activate not only aryl triflates as electrophiles, but also less reactive aryl mesylates, t
Synthesis of multisubstituted cycloalkenes through carbomagnesiation of strained cycloalkynes
Hosoya, Takamitsu,Karaki, Fumika,Minami, Yasunori,Nishiyama, Yoshitake,Sakata, Yuki,Tamura, Yuya,Yoshida, Suguru
supporting information, p. 7147 - 7150 (2020/07/21)
An efficient synthetic method of seven- and six-membered cycloalkenes through the generation of strained cycloalkynes and following carbomagnesiation is described. Further bond formations of the resulting cycloalkenylmagnesium intermediates with a wide variety of electrophiles enabled us to prepare diverse cycloalkene derivatives including benzoxepine analogs having a fully substituted alkene structure.
Enantioselective Copper Catalyzed Alkyne-Azide Cycloaddition by Dynamic Kinetic Resolution
Liu, En-Chih,Topczewski, Joseph J.
supporting information, p. 5135 - 5138 (2019/03/29)
The copper(I) catalyzed alkyne-azide cycloaddition (CuAAC), a click reaction, is one of the most powerful catalytic reactions developed during the last two decades. Conducting CuAAC enantioselectively would add a third dimension to this reaction and would
Lewis Acid Catalyzed Transfer Hydromethallylation for the Construction of Quaternary Carbon Centers
Walker, Johannes C. L.,Oestreich, Martin
supporting information, p. 15386 - 15389 (2019/10/28)
The design and gram-scale synthesis of a cyclohexa-1,4-diene-based surrogate of isobutene gas is reported. Using the highly electron-deficient Lewis acid B(C6F5)3, application of this surrogate in the hydromethallylation of electron-rich styrene derivatives provided sterically congested quaternary carbon centers. The reaction proceeds by C(sp3)?C(sp3) bond formation at a tertiary carbenium ion that is generated by alkene protonation. The possibility of two concurrent mechanisms is proposed on the basis of mechanistic experiments using a deuterated surrogate.
Cyclopentene Annulations of Alkene Radical Cations with Vinyl Diazo Species Using Photocatalysis
Sarabia, Francisco J.,Li, Qiankun,Ferreira, Eric M.
supporting information, p. 11015 - 11019 (2018/07/30)
A direct (3+2) cycloaddition between alkenes and vinyl diazo reagents using either Cr or Ru photocatalysis is described. The intermediacy of a radical cation species enables a nucleophilic interception by vinyl diazo compounds, a departure from their trad
Auto de-bromine-coupling reactions of 1-aryl-7-bromocycloheptenes
Lee, Gon-Ann,Lee, Hsin-Yi,Wang, Wen-Chieh,Cherng, Chih-Hwa
, p. 2956 - 2961 (2014/04/17)
Auto de-bromine-coupling reactions of 1-aryl-7-bromocycloheptenes to a new series of [7-6-6] tricyclic system were described. A variety of substituents at the para-position of the phenyl were amenable to this transformation, including electron-donating groups and halides. The presence of electron-donating groups resulted in a more efficient reaction, with higher yields than the case of halides.
Achieving vinylic selectivity in Mizoroki-heck reaction of cyclic olefins
Wu, Xiaojin,Lu, Yunpeng,Hirao, Hajime,Zhou, Jianrong
, p. 6014 - 6020 (2013/06/26)
In Heck reactions of cyclic olefins, the products usually have aryl groups that end up at the allylic and/or homoallylic position. We herein report new selectivity that adds aryl groups to the vinylic position. Cyclic olefins of various ring size worked well. The desired isomers were produced by palladium-hydride-catalyzed isomerization of the initial products. Thus, a specific catalyst must be used so that it can perform two jobs under one set of reaction conditions. Copyright
A one-pot preparation of aryl- and heteroarylcycloalkenes: Application to the total synthesis of (±)-laurokamurene B
Tallineau, Jean,Bashiardes, Georges,Coustard, Jean-Marie,Lecornué, Frédéric
experimental part, p. 2761 - 2764 (2010/03/03)
A general one-pot method has been developed for the preparation of various aryl- and heteroarylcycloalkenes. After lithiation of aryl and heteroaryl bromides followed by transmetalation with CeCl3, the organocerium addition to cycloalkanones proceeds clea
Arylation and vinylation of alkenes based on unusual sequential semipinacol rearrangement/Grob fragmentation of allylic alcohols
Yuan, Dao-Yi,Tu, Yong-Qiang,Fan, Chun-An
, p. 7797 - 7799 (2008/12/22)
(Chemical Equation Presented) Alkenes can be stereoselectively arylated and vinylated without transition-metal catalyst under mild conditions through an interesting NBS-promoted semipinacol rearrangement and a subsequent unusual NaOH-mediated Grob fragmentation.
