6266-99-5Relevant articles and documents
Deaminative Olefination of Methyl N-Heteroarenes by an Amine Oxidase Inspired Catalyst
Thorve, Pradip Ramdas,Maji, Biplab
supporting information, p. 542 - 547 (2021/01/26)
We explored the bioinspired o-quinone cofactor catalyzed aerobic primary amine dehydrogenation for a cascade olefination reaction with nine different methyl N-heteroarenes, including pyrimidines, pyrazines, pyridines, quinolines, quinoxolines, benzimidazoles, benzoxazoles, benzthiazoles, and triazines. An o-quinone catalyst phd (1,10-phenanthroline-5,6-dione) combined with a Br?nsted acid catalyzed the reaction. N-Heteroaryl stilbenoids were synthesized in high yields and (E)-selectivities under mild conditions using oxygen (1 atm) as the sole oxidant without needing transition-metal salt, ligand, stoichiometric base, or oxidant.
Oxidant-Controlled C-sp2/sp3-H Cross-Dehydrogenative Coupling of N-Heterocycles with Benzylamines
Sharma, Rohit,Abdullaha, Mohd,Bharate, Sandip B.
, p. 9786 - 9793 (2017/09/23)
Oxidant controlled ionic liquid mediated cross-dehydrogenative coupling (CDC) of benzylamines with N-heterocycles having sp2 or sp3 carbon resulted in the formation of C-benzoylated or alkenylated products. Benzoylation of N-heterocycles occurs via (NH4)2S2O8 catalyzed benzoyl radical formation. An oxidative alkenylation of N-heterocycles having C-sp3 carbon (2-methylaza-arenes) occurs via deamination of benzylamine followed by C-sp3-H bond activation in high stereoselectivity. Both benzoylation and alkenylation protocols are metal-free, green, simple, efficient, and tolerate a wide variety of functional groups.
Preparation of Vinyl Arenes by Nickel-Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides
Liu, Jiandong,Ren, Qinghua,Zhang, Xinghua,Gong, Hegui
supporting information, p. 15544 - 15548 (2016/12/09)
This work emphasizes the synthesis of substituted vinyl arenes by reductive coupling of aryl halides with vinyl bromides under mild and easy-to-operate nickel-catalyzed reaction conditions. A broad range of aryl halides, including heteroaromatics, and vinyl bromides were employed to yielding products in moderate to excellent yields with high functional-group tolerance. The nickel-catalytic system displays good chemoselectivity between the two C(sp2)-halide coupling partners, thus demonstrating a mechanistic pathway distinct from other stepwise protocols.
Development of unimolecular tetrakis(piperidin-4-ol) as a ligand for Suzuki-Miyaura cross-coupling reactions: Synthesis of incrustoporin and preclamol
Nallasivam, Jothi L.,Fernandes, Rodney A.
, p. 3558 - 3567 (2015/06/08)
Abstract A domino aza-Cope/aza-Prins cascade enabled the synthesis of a new class of 4-hydroxypiperidine-appended mono, bis, tris, and tetrakis unimolecular compounds that served as efficient ligands to catalyze Suzuki-Miyaura cross-coupling reactions under aerobic conditions. Various biaryls, terphenyls, and heterocyclic biphenyls were obtained in good to excellent yields. The ligands were also capable of catalyzing the Heck-Mizoroki reaction. As an application, the Suzuki-Miyaura coupling reaction was used in the synthesis of incrustoporin, its analogs, and the drug molecule preclamol. A domino aza-Cope/aza-Prins cascade enabled the synthesis of a new class of 4-hydroxypiperidine-appended mono-, bis-, tris-, and tetrakis-unimolecular compounds that served as efficient ligands to catalyze Suzuki-Miyaura cross-coupling reactions under aerobic conditions. Various biaryls, terphenyls, and heterocyclic biphenyls were obtained in good to excellent yields.
C(sp3)-H functionalization of methyl azaarenes: a calcium-catalyzed facile synthesis of (E)-2-styryl azaarenes and 2-aryl-1,3-bisazaarenes
Yaragorla, Srinivasarao,Singh, Garima,Dada, Ravikrishna
supporting information, p. 5924 - 5929 (2015/11/02)
Alkaline earth (Ca2+) catalyzed sp3 C-H functionalization of methyl azaarenes for the synthesis of biologically important (E)-2-styryl azaarenes, 2-aryl-1,3-bisazaarenes and 3,3-bisazaarenyl indolinones has been described. Initially methyl azaarenes react with aryl aldehydes to give β-hydroxy derivatives, which undergo Ca(II) catalyzed thermodynamic elimination to give the styryl azaarenes in a single step. Similarly it may undergo SN1 reaction to give 2-aryl-1,3-bisazaarenes and 3,3-bisazaarenyl indolinones (if isatin used as the electrophile). This green synthetic methodology enjoys the simple reaction procedures, solvent free conditions, step economy, substrate diversity and high yields of the products in short time.
Lewis-acid-catalyzed benzylic reactions of 2-methylazaarenes with aldehydes
Mao, Dan,Hong, Gang,Wu, Shengying,Liu, Xin,Yu, Jianjun,Wang, Limin
, p. 3009 - 3019 (2014/05/20)
Lewis-acid-catalyzed benzylic reactions of 2-methylazaarenes with aldehydes have been investigated. Series of azaarene derivatives were afforded by this reaction. 2-(Pyridin-2-yl)ethanols with common substituents were formed through the LiNTf2-promoted aldol reaction for the first time. 2-Alkenylpyridines, exclusively in the form of the E isomers, were synthesized in the presence of LiNTf2 cooperated with H2NTf. In the presence of La(Pfb)3 as catalysis, 2-alkenylquinolines were obtained in high yields through the reactions between 2-methylquinolines and aldehydes under air.
Iron-catalyzed C(sp3)-H functionalization of methyl azaarenes: A green approach to azaarene-substituted α- Or β-hydroxy carboxylic derivatives and 2-alkenylazaarenes
Pi, Danwei,Jiang, Kun,Zhou, Haifeng,Sui, Yuebo,Uozumi, Yasuhiro,Zou, Kun
, p. 57875 - 57884 (2015/01/08)
Bioactive azaarene-substituted lactic acids, β-hydroxy esters, 3-hydroxy-2H-indol-2-ones, and 2-alkenylazaarenes were prepared in moderate-to-excellent yields via C(sp3)-H functionalization of methyl azaarenes with carbonyl compounds in the presence of iron(ii) acetate as an inexpensive, nontoxic, efficient catalyst. The application of this atom-, step-economic, and environmentally friendly method was demonstrated by a gram-scale synthesis of 3-[(E)-2-(7-chloroquinolin-2-yl)vinyl]benzaldehyde, a key intermediate of leukotriene receptor antagonist (Montelukast).
Direct catalytic olefination of alcohols with sulfones
Srimani, Dipankar,Leitus, Gregory,Ben-David, Yehoshoa,Milstein, David
supporting information, p. 11092 - 11095 (2015/03/30)
The synthesis of terminal as well as internal olefins was achieved by the one-step olefination of alcohols with sulfones catalyzed by a ruthenium pincer complex. Furthermore performing the reaction with dimethyl sulfone under mild hydrogen pressure provides a direct route for the replacement of alcohol hydroxy groups by methyl groups in one step.
Transition-metal-free semihydrogenation of diarylalkynes: Highly stereoselective synthesis of trans -alkenes using Na2S·9H 2O
Chen, Zhengwang,Luo, Miaoting,Wen, Yuelu,Luo, Guotian,Liu, Liangxian
supporting information, p. 3020 - 3023 (2014/06/23)
A highly stereoselective and efficient transition-metal-free semihydrogenation of internal alkynes to E-alkenes using cheap and green water as hydrogen donor is described. The reactions are conducted under convenient conditions and provide products in good to excellent yields, with broad substrate scope, including a variety of diarylalkynes.
Nanocrystalline magnesium oxide-stabilized palladium(0): The Heck reaction of heteroaryl bromides in the absence of additional ligands and base
Kantam, Mannepalli Lakshmi,Redddy, Police Vishnuvardhan,Srinivas, Pottabathula,Venugopal, Akula,Bhargava, Suresh,Nishina, Yuta
, p. 2550 - 2554 (2013/09/24)
An efficient and user-friendly protocol has been realized for the Heck reaction of heteroaryl bromides by using a reusable nanocrystalline magnesium oxide-stabilized palladium(0) catalyst without the aid of additional ligands and base. Dimethylamine generated under in situ conditions by the decomposition of DMF serves as the base in this reaction. The catalyst was reused with consistent activity up to four cycles.
