21777-85-5Relevant academic research and scientific papers
Palladium-catalyzed dearomative allylation of indoles with cyclopropyl acetylenes: access to indolenine derivatives
Lu, Chuan-Jun,Chen, Yu-Ting,Wang, Hong,Li, Yu-Jin
, p. 635 - 644 (2021/02/06)
A palladium-catalyzed redox-neutral allylic alkylation of indoles with cyclopropyl acetylenes has been disclosed. Various 1,3-diene indolenine framework bearing a quaternary stereocenter at the C3 position were synthesized straightforwardly in good to excellent yields with high regio- and stereoselectivities. The reaction could be further expanded to the dearomatization of naphthols to synthesize functionalized cyclohexadienones with 1,3-diene motifs. The reaction exhibited high atom economy and good functional group tolerance.
1- And 2-Azetines via Visible Light-Mediated [2 + 2]-Cycloadditions of Alkynes and Oximes
Becker, Marc R.,Blackmun, Dominique E.,Schindler, Corinna S.,Wearing, Emily R.
supporting information, p. 16235 - 16242 (2021/10/20)
Azetines, four-membered unsaturated nitrogen-containing heterocycles, hold great potential for drug design and development but remain underexplored due to challenges associated with their synthesis. We report an efficient, visible light-mediated approach
Regio- And stereoselective electrochemical synthesis of sulfonylated enethers from alkynes and sulfonyl hydrazides
Du, Wu-Bo,Wang, Ning-Ning,Pan, Chao,Ni, Shao-Fei,Wen, Li-Rong,Li, Ming,Zhang, Lin-Bao
supporting information, p. 2420 - 2426 (2021/04/07)
An electrooxidative direct difunctionalization of internal alkynes with sulfonyl hydrazides has been developed for the construction of sulfonated enethers. In this transformation, metal catalysts or stoichiometric amount of oxidants are not required and molecular nitrogen and hydrogen are the sole byproducts, providing a simple and green approach for preparing various sulfonyl tetrasubstituted alkenes. Notably, the protocol could be efficiently scaled up and the follow-up procedures of the corresponding functionalized alkenes demonstrate the practicality of the electrochemical synthesis.
Reaction of Alkynyl- And Alkenyltrifluoroborates with Propargyldicobalt Cations: Alkynylation, Alkenylation, and Cyclopropanation Product Pathways
Battersby, Jeffrey,Green, James R.,St Onge, Brent,Taimoory, S. Maryamdokht,Trant, John F.
, p. 18094 - 18106 (2021/12/13)
The Lewis acid-mediated Nicholas reactions of propargyl acetate–Co2(CO)6 complexes with a series of potassium alkynyltrifluoroborates and potassium alkenyltrifluoroborates are described. Alkynyltrifluoroborates directly alkynylate the intermediate propargyldicobalt cations. In contrast, alkenyltrifluoroborates proceed through one of the three modes of dominant reactivity: C-2-substituted alkenyltrifluorobrates directly alkenylate, predominantly with the retention of stereochemistry. C-1-substituted alkenyltrifluoroborates alkenylate at C-2. Potassium vinyltrifluoroborate incorporates a cyclopropane at the site propargyl to alkynedicobalt. Computational analysis of these systems explains the differential modes of reactivity of alkenyltrifluoroborates and outlines the probable mechanisms for the formation of each product.
Stereospecific Electrophilic Fluorocyclization of α,β-Unsaturated Amides with Selectfluor
Fei, Haiyang,Fu, Yao,Jalani, Hitesh B.,Li, Guigen,Lu, Hongjian,Wu, Hongmiao,Xu, Zheyuan,Zhu, Lin
supporting information, (2020/03/30)
An efficient fluorocyclization of α,β-unsaturated amides through a formal halocyclization process is developed. The reaction proceeds under transition-metal-free conditions and leads to the formation of fluorinated oxazolidine-2,4-diones with excellent regio- and diastereoselectivity. The evaluation of the reaction mechanism based on preliminary experiments and density functional theory calculations suggests that a synergetic syn-oxo-fluorination occurs and is followed by an anti-oxo substitution reaction. The reaction opens a new window in the field of stereospecific fluorofunctionalization.
Nickel-Catalyzed Allylmethylation of Alkynes with Allylic Alcohols and AlMe3: Facile Access to Skipped Dienes and Trienes
Li, Jincan,Li, Wanfang,Yu, Shun,Zhao, Yu
supporting information, p. 14404 - 14408 (2020/07/04)
We present herein an unprecedented allylative dicarbofunctionalization of alkynes with allylic alcohols. This simple catalytic procedure utilizes commercially available Ni(COD)2, triphenylphosphine, and inexpensive reagents, and delivers valuable skipped dienes and trienes with an all-carbon tetrasubstituted alkene unit in a highly stereoselective fashion. Preliminary mechanistic studies support the reaction pathway of allylnickelation followed by transmetalation in this dicarbofunctionalization of alkynes.
Phosphorus(III)-Mediated, Tandem Deoxygenative Geminal Chlorofluorination of 1,2-Diketones
Choi, Garam,Chung, Won-Jin,Hwang, Sunjoo,Jang, Hanna,Kim, Ha Eun
supporting information, p. 4190 - 4195 (2020/06/27)
Tetrasubstituted carbon containing two different halogen substituents was constructed in a single-step operation by utilizing the carbene-like reactivity of dioxaphospholene through the tandem reaction of electrophilic and nucleophilic halogenating reagents. It was crucial to devise non-dealkylatable phosphoramidite, which enabled the efficient formation of geminal chlorofluorides from various 1,2-diketones with (PhSO2)2NF and n-Bu4NCl. In addition, selective functionalization of the chlorine substituent was demonstrated, and the absence of halogen scrambling was confirmed.
Palladium-Catalyzed Tunable Carbonylative Synthesis of Enones and Benzofulvenes
Peng, Jin-Bao,Wu, Fu-Peng,Spannenberg, Anke,Wu, Xiao-Feng
supporting information, p. 8696 - 8700 (2019/08/01)
A palladium-catalyzed four-component carbonylative coupling reaction involving aryl halides, internal alkynes, arylboronic acids, and CO has been developed for the first time. All-carbon substituted α-unsaturated ketones and benzofulvenes can be selectively obtained in a highly regio- and stereocontrolled manner. Using Cu(TFA)2 as the additive, a series of tetrasubstituted α-unsaturated ketones were prepared in moderate to high yields. Using more acidic Lewis acid Cu(OTf)2 as the additive, multisubstituted benzofluvenes were synthesized in moderate yields. This efficient methodology involved the formation of three new C?C bonds, and provided a divergent method for the quick construction of multisubstituted α-unsaturated ketones and benzofulvenes from easily available starting materials.
C-H alkenylation/cyclization and sulfamidation of 2-phenylisatogens using: N -oxide as a directing group
Guo, Lingmei,Tang, Baolan,Nie, Ruifang,Liu, Yanzhao,Lv, Shan,Wang, Huijing,Guo, Li,Hai, Li,Wu, Yong
supporting information, p. 10623 - 10626 (2019/09/06)
The first example of transition-metal-catalyzed C-H activations of 2-phenylisatogens with alkynes and sulfonyl azides has been developed using N-oxide as the directing group. Ru(ii)-Catalyzed C-H alkenylation/cyclization and Ir(iii)-catalyzed direct C-H sulfamidation proceeded with good yields and excellent functional group tolerance. Importantly, these two transformations provided straightforward routes for the synthesis of indol-3-one derivatives and sulfamidated 2-phenylisatogens respectively, which might be of considerable bioactivities.
Sustainable dipolar homo-dicopper (II) dihydrazone complex as a catalyst for Sonogashira cross couplings
Adam, Mohamed Shaker S.
, (2019/11/02)
A novel dicopper (II) complex, Cu2L, was prepared form the complexation of the new polydentate ligand (H4L), bis(sodium 3-formyl-4-hydroxybenzenesulfonate)succinylhydrazone, with copper acetate. The novel homobinuclear complex was quite characterized by various physico-chemical tools and employed as a homogeneous and efficient-green catalyst for Sonogashira cross-couplings of phenylacetylene with halobenzenes under sustainable conditions. Cu2L exhibited very good catalytic performance with excellent chemoselectivity. The catalytic efficiency of Cu2L was improved by using ionic liquids–aqueous media (1: 1, binary mixture). A mechanistic pathway was also proposed for Cu(II)-catalyzed Sonogashira cross-coupling reactions for the reported finding. DFT for H4L and Cu2L were studied. Electronic configurations, energy of HOMO and LUMO orbitals, energy gap between orbitals (ΔE), electronegativity, hardness and softness were also calculated and compared with the applicable catalytic findings of Cu2L, which are in good conformity.
