18303-04-3Relevant articles and documents
Synthesis, catalytic activity and redox properties of palladium(0) complexes with 15-membered triolefinic macrocyclic ligands containing one, two or three ferrocenyl groups
Llobet, Antoni,Masllorens, Ester,Moreno-Ma?as, Marcial,Pla-Quintana, Anna,Rodríguez, Montserrat,Roglans, Anna
, p. 1425 - 1428 (2002)
A series of 15-membered triolefinic macrocycles containing ferrocenyl groups and their palladium(0) complexes have been synthesized and characterized. Their catalytic activity has been demonstrated in Suzuki-type cross-coupling and in the Heck reaction. Their redox properties have been investigated by means of cyclic voltammetry.
Nickel-Catalyzed C(sp3)-H Functionalization of Benzyl Nitriles: Direct Michael Addition to Terminal Vinyl Ketones
Zhang, Ninghui,Zhang, Chunli,Hu, Xiaoping,Xie, Xin,Liu, Yuanhong
supporting information, p. 6004 - 6009 (2021/07/31)
An efficient nickel(0)-catalyzed addition of benzyl nitriles to terminal vinyl ketones via C(sp3)-H functionalization has been developed. The reaction provides a novel and efficient protocol for the synthesis of α-functionalized benzyl nitriles with a wide range of structural diversity under mild reaction conditions while obviating the use of a strong base. The work might be potentially useful toward the development of an enantioselective variant using chiral nitrogen ligands.
Synthesis method of azetidine silicon precursor compound and method for synthesizing six-membered silicon-nitrogen heterocyclic compound by using azetidine silicon precursor compound
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Paragraph 0091-0095, (2021/06/26)
The invention discloses a synthesis method of an azetidine silicon precursor compound and a method for synthesizing a six-membered silicon nitrogen heterocyclic compound by using the azetidine silicon precursor compound, and belongs to the technical field
A Radical-Initiated Fragmentary Rearrangement Cascade of Ene-Ynamides to [1,2]-Annulated Indoles via Site-Selective Cyclization
Li, Sifan,Wang, Yu,Wu, Zibo,Shi, Weiliang,Lei, Yibo,Davies, Paul W.,Shu, Wei
supporting information, p. 7209 - 7214 (2021/09/14)
Straightforward access to [1,2]-annulated indoles, key substructures in natural products, is highly desirable yet challenging. Herein, a radical triggered fragmentary cyclization cascade reaction of ene-ynamides is presented, providing a rapid access into [1,2]-annulated indoles by an intermolecular radical addition, intramolecular cyclization, desulfonylative aryl migration, and site-selective C(sp2)-N cyclization sequence. DFT calculations support oxidation of N-centered radical species to cations prior to the C-N bond formation, followed by an unusual aza-Nazarov cyclization.
DirectN-glycosylation of tosyl and nosyl carbamates with trichloroacetimidate donors
Khanam, Ariza,Mandal, Pintu Kumar
supporting information, p. 15386 - 15391 (2021/09/07)
Under catalyst and additive-free conditions, a convenient and highly efficient eco-friendly method for the stereoselective synthesis ofN-glycofuranosyl and glycofuranosyl sulfonamides has been developed. The two-component reaction of glycofuranosyl trichloroacetimidates with a wide range of tosyl and nosyl carbamate acceptors having varying pKa-values including non-sugar-, and sugar-derived carbamates as well as amino acid-derived carbamates, proceeded smoothly with good yield and β-stereoselectivity. In addition, the selective deprotection ofN-carbamates andN-sulfonyl groups of theN-glycoside functioning as orthogonal protective groups was performed for further functionalization of theN-glycosides.
Ni/AntPohs-Catalyzed Stereoselective Asymmetric Intramolecular Reductive Coupling of N-1,6-Alkynones
Chen, Wanjun,Cheng, Yaping,Zhang, Tao,Mu, Yu,Jia, Wenqi,Liu, Guodu
, p. 5166 - 5182 (2021/05/05)
An efficient nickel-catalyzed stereoselective asymmetric intramolecular reductive coupling of N-1,6-alkynones is reported. A P-chiral monophosphine ligand AntPhos was found to be a privileged catalyst for constructing versatile functionalized chiral pyrro
Alkene Syn- And Anti-Oxyamination with Malonoyl Peroxides
Curle, Jonathan M.,Perieteanu, Marina C.,Humphreys, Philip G.,Kennedy, Alan R.,Tomkinson, Nicholas C. O.
supporting information, p. 1659 - 1664 (2020/02/13)
Malonoyl peroxide 6 is an effective reagent for the syn- or anti-oxyamination of alkenes. Reaction of 6 and an alkene in the presence of O-tert-butyl-N-tosylcarbamate (R3 = CO2 tBu) leads to the anti-oxyaminated product in up to 99% yield. Use of O-methyl-N-tosyl carbamate (R3 = CO2Me) as the nitrogen nucleophile followed by treatment of the product with trifluoroacetic acid leads to the syn-oxyaminated product in up to 77% yield. Mechanisms consistent with the observed selectivities are proposed.
An unconventional sulfur-to-selenium-to-carbon radical transfer: Chemo-and regioselective cyclization of yne-ynamides
Dutta, Shubham,Prabagar,Vanjari, Rajeshwer,Gandon, Vincent,Sahoo, Akhila K.
supporting information, p. 1113 - 1118 (2020/03/11)
An uncommon sulfur → selenium → carbon radical transfer process is employed to develop an unprecedented selenyl radical-mediated regioselective cyclization of yne-tethered-ynamides. Density functional theory studies and HRMS experiments are used to establish a reactivity scale between thiyl and selenyl radicals. The unique features of this transformation include, (1) the chemoselective reactivity of RSe over RS, (2) regioselective RSe attack on alkyne over ynamide, (3) 5-exo-dig cyclization of yne-ynamide to unusual 4-selenyl-pyrroles, and (4) the green synthetic method. The reaction of methyldiselenide with yne-ynamides to methylselenopyrroles is also described.
Alkyne Versus Ynamide Reactivity: Regioselective Radical Cyclization of Yne-Ynamides
Dutta, Shubham,Mallick, Rajendra K.,Prasad, Rangu,Gandon, Vincent,Sahoo, Akhila K.
supporting information, p. 2289 - 2294 (2019/01/25)
Ynamides are typically more reactive than simple alkynes and olefins. However, a serendipitous observation revealed a rare case where the reactivity of simple alkynes exceeds that of ynamides. This led to the development of a unique sulfur-radical-triggered cyclization of yne-tethered ynamides, which involves attack of the alkyne by a thiyl radical followed by cyclization with the ynamide. A wide range of novel 4-thioaryl pyrroles that could tolerate common functional moieties and N-protecting groups were expediently constructed by this strategy. The current method contrasts with the typical cyclization of yne-ynamides, which involves the attack of the alkyne moiety by the ynamide core. Control experiments and DFT calculations supported the participation of the sulfur radical in the reaction and the regioselective cyclization. The synthetic potential of the substituted pyrroles is also discussed.
Self-promoted and stereospecific formation of N-glycosides
Nielsen, Michael Martin,Ma?a, Patrycja,Baldursson, Eirikur Pórir,Pedersen, Christian Marcus
, p. 5299 - 5307 (2019/05/29)
A stereoselective and self-promoted glycosylation for the synthesis of various N-glycosides and glycosyl sulfonamides from trichloroacetimidates is presented. No additional catalysts or promoters are needed in what is essentially a two-component reaction. When α-glucosyl trichloroacetimidates are employed, the reaction resulted in the stereospecific formation of the corresponding β-N-glucosides in high yields at ambient conditions. On the other hand, when equatorial glucosyl donors were used, the stereospecificity decreased and resulted in a mixture of anomers. By NMR-studies, it was concluded that this decrease in stereospecificity was due to an, until now, unpresented anomerization of the trichloroacetimidate under the very mildly acidic conditions. The mechanism and kinetics of the glycosylations have been studied by NMR-experiments, which gave an insight into the activation of trichloroacetimidates, suggesting an SNi-like mechanism involving ion pairs. The scope of glycosyl donors and sulfonamides was found to be very broad including popular N-protective groups and common glycosyl donors of various reactivity. Peracetylated GlcNAc trichloroacetimidate could be used without the need for any promotors or additives and a tyrosine side chain was glycosylated as an N-glycosyl carbamate. The N-carbamates and the N-sulfonyl groups functioned as orthogonal protective groups of the N-glycoside and hence allowed further N-functionalization without risking mutarotation of the N-glycoside. The N-glycosylation was also performed on a gram scale, without a drop in stereoselectivity nor yield.