- Aza-heterocycles via copper-catalyzed, remote C–H desaturation of amines
-
A majority of medicines contain a nitrogen atom within a five- or six-membered ring. To rapidly access both such aza-heterocycles, we sought to develop a remote C–H desaturation of amines. Inspired by the Hofmann-L?ffler-Freytag (HLF) synthesis of five-me
- Dare, Ross M.,Nagib, David A.,Paneque, Alyson N.,Stateman, Leah M.
-
supporting information
p. 210 - 224
(2022/01/19)
-
- Rhodium(III)-Catalyzed Synthesis of Skipped Enynes via C(sp3)–H Alkynylation of Terminal Alkenes
-
The RhIII-catalyzed allylic C?H alkynylation of non-activated terminal alkenes leads selectively to linear 1,4-enynes at room-temperature. The catalytic system tolerates a wide range of functional groups without competing functionalization at other positions. Similarly, the vinylic C?H alkynylation of α,β- and β,γ- unsaturated amides gives conjugated Z-1,3-enynes and E-enediynes.
- Della-Felice, Franco,Zanini, Margherita,Jie, Xiaoming,Tan, Eric,Echavarren, Antonio M.
-
supporting information
p. 5693 - 5698
(2021/02/09)
-
- Au(I)-Catalyzed Oxidative Functionalization of Yndiamides
-
Yndiamides, underexplored cousins of ynamides, offer rich synthetic potential as doubly nitrogenated two carbon building blocks. Here we report a gold-catalyzed oxidative functionalization of yndiamides to access unnatural amino acid derivatives, using a wide range of nucleophiles as a source of the amino acid side chain. The transformation proceeds under mild conditions, is highly functional group tolerant, and displays excellent regioselectivity through subtle steric differentiation of the yndiamide nitrogen atom substituents.
- Tong, Zixuan,Garry, Olivia L.,Smith, Philip J.,Jiang, Yubo,Mansfield, Steven J.,Anderson, Edward A.
-
supporting information
p. 4888 - 4892
(2021/06/28)
-
- Practical Synthesis of Halogenated N-Heterocycles via Electrochemical Anodic Oxidation of Unactivated Alkenes
-
A general and efficient intramolecular halo-amination of unactivated alkenes for the synthesis of various halogenated N-heterocycles was developed via electrochemical anodic oxidation. This protocol proceeds in a simple undivided cell by employing LiI or LiBr as redox mediums and halogen sources. A wide range of halogenated N-heterocycles, including three-, five-, and six-membered N-heterocycles were constructed in moderate to good yields at room temperature. Notably, this electrochemical oxidative transformation avoids the utilization of external oxidants and strong bases, therefore represents an environmentally benign approach.
- He, Xinxu,He, Yanyang,Qin, Xiaowen,Wu, Xiao-Feng,Yin, Zhiping
-
supporting information
p. 5831 - 5834
(2021/11/17)
-
- A Radical-Initiated Fragmentary Rearrangement Cascade of Ene-Ynamides to [1,2]-Annulated Indoles via Site-Selective Cyclization
-
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.
- Li, Sifan,Wang, Yu,Wu, Zibo,Shi, Weiliang,Lei, Yibo,Davies, Paul W.,Shu, Wei
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p. 7209 - 7214
(2021/09/14)
-
- Highly selective hydrosilylation of equilibrating allylic azides
-
The Pt-catalyzed hydrosilylation of equilibrating allylic azides is reported. The reaction provides only one out of four possible hydrosilylation products in good yields and with very high chemoselectivity (alk-1-enevs.alk-2-ene), regioselectivity (linearvs.branched), and excellent functional group tolerance.
- Liu, Ruzhang,Liu, Yongmei,Wang, Juan,Wei, Zhen,Xue, Huaiguo
-
supporting information
p. 5038 - 5041
(2020/05/18)
-
- Synthesis method of 3-azidopropylsilane
-
The invention discloses a synthetic method of 3-azidopropylsilane, wherein the method comprises the steps: firstly, allyl azide is synthesized by allyl bromide, and because the allyl azide is easy togenerate [3,3] rearrangement reaction at room temperatur
- -
-
Paragraph 0086; 0087
(2020/06/05)
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- Copper-Catalyzed Carbonylative Synthesis of β-Homoprolines from N-Fluoro-sulfonamides
-
A new methodology for the carbonylative transformation of N-fluoro-sulfonamides into N-sulfonyl-β-homoproline esters has been described. In the presence of a catalytic amount of Cu(OTf)2, a range of β-homoproline derivatives were prepared in moderate to good yield. The reaction proceeds via the intramolecular cyclization and intermolecular carbonylation of a free carbon radical. Notably, this procedure offers the possibility to build potential functionalized bioactive molecules.
- Wu, Xiao-Feng,Yin, Zhiping,Zhang, Youcan
-
supporting information
p. 1889 - 1893
(2020/03/24)
-
- Gold(I)/Gold(III) Catalysis that Merges Oxidative Addition and π-Alkene Activation
-
Heteroarylation of alkenes with aryl iodides was efficiently achieved with a (MeDalphos)AuCl complex through AuI/AuIII catalysis. The possibility to combine oxidative addition of aryl iodides and π-activation of alkenes at gold is demonstrated for the first time. The reaction is robust and general (>30 examples including internal alkenes, 5-, 6-, and 7-membered rings). It is regioselective and leads exclusively to trans addition products. The (P,N) gold complex is most efficient with electron-rich aryl substrates, which are troublesome with alternative photoredox/oxidative approaches. In addition, it provides a very unusual switch in regioselectivity from 5-exo to 6-endo cyclization between the Z and E isomers of internal alkenols.
- Amgoune, Abderrahmane,Bourissou, Didier,Rigoulet, Mathilde,Thillaye du Boullay, Olivier
-
p. 16625 - 16630
(2020/07/24)
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- CpTiCl2-Catalyzed Cross-Coupling between Internal Alkynes and Ketones: A Novel Concept in the Synthesis of Halogenated, Conjugated Dienes
-
A novel concept for the synthesis of halogenated, conjugated dienes is disclosed: the CpTiCl2-catalyzed coupling of keto-alkynes, in the presence of Me3SiBr/Et3N?HBr. This reaction provided five-, six-, and seven-membered
- Roldan-Molina, Esther,Nievas, Maria M.,Navarro, Jorge A. R.,Oltra, J. Enrique
-
supporting information
p. 8296 - 8301
(2020/06/17)
-
- Intermolecular Anti-Markovnikov Hydroamination of Unactivated Alkenes with Sulfonamides Enabled by Proton-Coupled Electron Transfer
-
Here we report a catalytic method for the intermolecular anti-Markovnikov hydroamination of unactivated alkenes using primary and secondary sulfonamides. These reactions occur at room temperature under visible light irradiation and are jointly catalyzed by an iridium(III) photocatalyst, a dialkyl phosphate base, and a thiol hydrogen atom donor. Reaction outcomes are consistent with the intermediacy of an N-centered sulfonamidyl radical generated via proton-coupled electron transfer activation of the sulfonamide N-H bond. Studies outlining the synthetic scope (>60 examples) and mechanistic features of the reaction are presented.
- Zhu, Qilei,Graff, David E.,Knowles, Robert R.
-
supporting information
p. 741 - 747
(2018/01/26)
-
- Intermolecular Palladium-Catalyzed Oxidative Fluorocarbonylation of Unactivated Alkenes: Efficient Access to β-Fluorocarboxylic Esters
-
A novel palladium-catalyzed intermolecular oxidative fluorocarbonylation of alkenes has been developed, in which employment of a cooperative process with electrophilic ArIF2-meidated alkenes activation and palladium-catalyzed carbonylation is c
- Qi, Xiaoxu,Yu, Feng,Chen, Pinhong,Liu, Guosheng
-
supporting information
p. 12692 - 12696
(2017/10/06)
-
- Synthetic efforts toward the Lycopodium alkaloids inspires a hydrogen iodide mediated method for the hydroamination and hydroetherification of olefins
-
Progress toward the total syntheses of a diverse set of fawcettimine-type Lycopodium alkaloids via a "Heathcock-type" 6-5-9 tricycle is disclosed. This route features an intermolecular Diels-Alder cycloaddition to rapidly furnish the 6-5-fused bicycle and a highly chemoselective directed hydrogenation to build the azonane fragment. While conducting these synthetic studies, trimethylsilyl iodide was found to effect a hydroamination reaction to furnish the tetracyclic core of serratine and related natural products. This observation has been expanded into a general method for the room temperature hydroamination of unactivated olefins with tosylamides utilizing catalytic "anhydrous" HI (generated in situ from trimethylsilyl iodide and water). The presence of the iodide anion is critical to the success of this Bronsted acid catalyzed protocol, possibly due to its function as a weakly coordinating anion. These conditions also effect the analogous hydroetherification reaction of alcohols with unactivated olefins.
- Leger, Paul R.,Murphy, Rebecca A.,Pushkarskaya, Eugenia,Sarpong, Richmond
-
p. 4377 - 4383
(2015/03/14)
-
- Photoredox-Catalyzed Intramolecular Aminodifluoromethylation of Unactivated Alkenes
-
A photoredox catalyzed aminodifluoromethylation of unactivated alkenes has been developed in which HCF2SO2Cl is used as the HCF2 radical source. Sulfonamides were active nucleophiles in the final step of a tandem addition/oxidation/cyclization process to form pyrrolidines, and esters were found to cyclize to form lactones. Thus, a variety of pyrrolidines and lactones were obtained in moderate to excellent yield. In order for the cyclization reactions to be efficient, a combination of a copper catalyst (Cu(dap)2Cl) and silver carbonate was crucial to suppressing a competing chloro, difluoroalkylation process.
- Zhang, Zuxiao,Tang, Xiaojun,Thomoson, Charles S.,Dolbier, William R.
-
supporting information
p. 3528 - 3531
(2015/07/28)
-
- Palladium-Catalyzed Alkene Carboamination Reactions of Electron-Poor Nitrogen Nucleophiles
-
Modified reaction conditions that facilitate Pd-catalyzed alkene carboamination reactions of electron-deficient nitrogen nucleophiles are reported. Pent-4-enylamine derivatives bearing N-tosyl or N-trifluoroacetyl groups are coupled with aryl triflates to
- Peterson, Luke J.,Wolfe, John P.
-
p. 2339 - 2344
(2015/07/27)
-
- Ti-catalyzed straightforward synthesis of exocyclic allenes
-
Exocyclic allenes constitute useful building blocks in organic synthesis and have recently been identified as key intermediates in the synthesis of natural products. Here the first general method for the most straightforward synthesis of exocyclic allenes
- Munoz-Bascon, Juan,Hernandez-Cervantes, Carmen,Padial, Natalia M.,Alvarez-Corral, Miriam,Rosales, Antonio,Rodriguez-Garcia, Ignacio,Oltra, J. Enrique
-
p. 801 - 810
(2014/01/23)
-
- Ring-closing metathesis of vinyl fluorides towards α-fluorinated α,β-unsaturated lactams and lactones
-
Ring-closing olefin metathesis reactions (RCM) using Grubbs II or Hoveyda's catalysts have been applied to a series of N-alkenyl-N-benzyl-α-fluoroacrylamides. α-Fluoro-α,β-unsaturated γ- or δ-lactams incorporating a fluorinated double bond were obtained in moderate to good yields, depending on the nature of substituents on the benzyl ring. The corresponding seven- and eight-membered lactams were not formed under similar conditions. When the N-benzyl group was replaced by an N-tosyl group, the corresponding ε-lactam was also formed in 38% yield. When N-(2-fluoroallyl) derivatives were used instead of fluoroacryloyl derivatives, six-, seven-, and eight-membered N-heterocycles were obtained in low yields. This method was also used to synthesize fluorinated α,β-unsaturated analogues of pyrrolizidine and indolizidine alkaloids from prolinol, and also to synthesize N-benzyl-3-fluoroquinolone in three steps from commercially available 2-vinylaniline in 44% overall yield. Also 3-fluorocoumarin and 3-fluorochromene were prepared from ovinylphenol, and 3-fluoro-benzoxepine was available from o-allylphenol.
- Marhold, Michael,Stillig, Christian,Fr?hlich, Roland,Haufe, Günter
-
supporting information
p. 5777 - 5785
(2014/10/15)
-
- Efficient copper-catalyzed direct intramolecular aminotrifluoromethylation of unactivated alkenes with diverse nitrogen-based nucleophiles
-
A mild, convenient, and step-economical intramolecular aminotrifluoromethylation of unactivated alkenes with a variety of electronically distinct, nitrogen-based nucleophiles in the presence of a simple copper salt catalyst, in the absence of extra ligand
- Lin, Jin-Shun,Xiong, Ya-Ping,Ma, Can-Liang,Zhao, Li-Jiao,Tan, Bin,Liu, Xin-Yuan
-
p. 1332 - 1340
(2014/04/03)
-
- Regioselective copper(II)-mediated bromoamination of unfunctionalized olefins: An efficient route to N-heterocyclic compounds
-
Bromoamination of unfunctionalized olefins was realized under mild conditions using copper(II) bromide (CuBr2) as both reaction promoter and bromine source. The reactions could be carried out under open air at ambient temperature, and both N-alkylated and N-tosylated substrates could be converted to the corresponding N-heterocyclic compounds in high regioselectivity and good isolated yields. A variety of biologically important structures could be obtained via subsequent nucleophilic substitution reactions.
- Liu, Gong-Qing,Ding, Zhen-Ying,Zhang, Li,Li, Ting-Ting,Li, Lin,Duan, Lili,Li, Yue-Ming
-
supporting information
p. 2303 - 2310
(2014/07/21)
-
- Copper-catalyzed sulfonamides formation from sodium sulfinates and amines
-
A new and convenient method for the construction of sulfonamides via a copper-catalyzed oxidative coupling between sodium sulfinates and amines with 1 atm O2 or DMSO as the oxidant was described. This method provides efficient and robust synthesis of functional sulfonamides in good yields and excellent chemoselectivity. And detailed mechanistic studies showed that this transformation may go through a single electron transfer (SET) pathway.
- Tang, Xiaodong,Huang, Liangbin,Qi, Chaorong,Wu, Xia,Wu, Wanqing,Jiang, Huanfeng
-
supporting information
p. 6102 - 6104
(2013/07/11)
-
- Copper-catalyzed enantioselective intramolecular alkene amination/intermolecular heck-type coupling cascade
-
Enantioselective copper-catalyzed cyclization of γ- alkenylsulfonamides and a δ-alkenylsulfonamide in the presence of a range of vinyl arenes results in variously functionalized 2-substituted chiral nitrogen heterocycles via a formal alkene C-H functionalization process. Application of this reaction to the concise synthesis of a 5-HT7 receptor antagonist is demonstrated.
- Liwosz, Timothy W.,Chemler, Sherry R.
-
p. 2020 - 2023
(2012/03/12)
-
- Synthesis of 3-fluoropyrrolidines and 4-fluoropyrrolidin-2-ones from allylic fluorides
-
Various 3-fluoropyrrolidines and 4-fluoropyrrolidin-2-ones were prepared by 5-exo-trig iodocyclisation from allylic fluorides bearing a pending nitrogen nucleophile. These bench-stable precursors were made accessible upon electrophilic fluorination of the
- Combettes, Lorraine E.,Schuler, Marie,Patel, Rakesh,Bonillo, Baltasar,Odell, Barbara,Thompson, Amber L.,Claridge, Tim D. W.,Gouverneur, Véronique
-
p. 13126 - 13132
(2013/01/15)
-
- Catalytic enantioselective alkene aminohalogenation/cyclization involving atom transfer
-
Problem solved: The title reaction was used for the synthesis of chiral 2-bromo, chloro, and iodomethyl indolines and 2-iodomethyl pyrrolidines (see scheme). Stereocenter formation is believed to occur by enantioselective cis aminocupration and C-X bond formation is believed to occur by atom transfer. The ultility of the products as versatile synthetic intermediates was demonstrated, as was a radical cascade cyclization sequence. Copyright
- Bovino, Michael T.,Chemler, Sherry R.
-
supporting information; body text
p. 3923 - 3927
(2012/05/20)
-
- Reversible alkene insertion into the Pd-N bond of Pd(II)-sulfonamidates and implications for catalytic amidation reactions
-
Alkene insertion into Pd-N bonds is a key step in Pd-catalyzed oxidative amidation of alkenes. A series of well-defined Pd(II)-sulfonamidate complexes have been prepared and shown to react via insertion of a tethered alkene. The Pd-amidate and resulting P
- White, Paul B.,Stahl, Shannon S.
-
supporting information; experimental part
p. 18594 - 18597
(2012/01/31)
-
- Gold-catalyzed intramolecular aminoarylation of alkenes: C-C bond formation through bimolecular reductive elimination
-
(Chemical equation presented) Gold-ilocks and the 3 mol% catalyst: Bimetallic gold bromides allow the room temperature aminoarylation of unactivated terminal olefins with aryl boronic acids using Selectfluor as an oxidant. A catalytic cycle involving gold (I)/gold(III) and a bimolecular reductive elimination for the key C-C bond-forming step is proposed, dppm= bis(diphenylphosphanyl) methane.
- Brenzovich Jr., William E.,Benitez, Diego,Lackner, Aaron D.,Shunatona, Hunter P.,Tkatchouk, Ekaterina,Goddard III, William A.,Toste, F. Dean
-
supporting information; experimental part
p. 5519 - 5522
(2010/09/05)
-
- Homogeneous gold-catalyzed oxidative carboheterofunctionalization of alkenes
-
(Chemical Equation Presented) Homogeneous carboamination, carboalkoxylation and carbolactonization of terminal alkenes are realized via oxidative gold catalysis, providing expedient access to various substituted Nor O-heterocycles. Deuterium-labeling studies established the anti nature of the alkene functionalization and the indispensible role of Au(I)/Au(III) catalysis. This study constitutes the first example of catalytically converting C(sp 3)-Au bonds into C(sp3)-C(sp2) bonds in a crosscoupling manner and opens new opportunities to study gold alkene catalysis where alkylgold intermediates can be readily functionalized intermolecularly. Copyright
- Zhang, Guozhu,Cui, Li,Wang, Yanzhao,Zhang, Liming
-
supporting information; experimental part
p. 1474 - 1475
(2010/04/04)
-
- Asymmetric allylic alkylation in combination with ring-closing metathesis for the preparation of chiral N-heterocycles
-
Asymmetric copper-catalyzed allylic substitution with methylmagnesium bromide is employed in combination with ring-closing olefin metathesis or ene - yne metathesis to achieve the synthesis of chiral, unsaturated nitrogen heterocycles. The resulting six-
- Teichert, Johannes F.,Zhang, Suyan,Van Zijl, Anthoni W.,Slaa, Jan Willem,Minnaard, Adriaan J.,Feringa, Ben L.
-
supporting information; experimental part
p. 4658 - 4660
(2010/12/19)
-
- Enamide-benzyne-[2 + 2] cycloaddition: Stereoselective tandem [2 + 2]-pericyclic ring-opening-intramolecular N-tethered [4 + 2] cycloadditions
-
Image Presented Benzyne-[2 + 2] cycloadditions with enamides are described. This effort led to the development of a highly stereoselective tandem [2 + 2] cycloaddition-pericyclic ring-opening-intramolecular-N-tethered-[4 + 2] cycloaddition for rapid assembly of nitrogen heterocycles.
- Feltenberger, John B.,Hayashi, Ryuji,Tang, Yu,Babiash, Eric S.C.,Hsung, Richard P.
-
supporting information; experimental part
p. 3666 - 3669
(2011/02/25)
-
- Copper(II)-catalyzed enantioselective intramolecular carboamination of alkenes
-
The enantioselective oxidative cyclizations of γ-alkenyl arylsulfonamides and a δ-alkenyl arylsulfonamide for the synthesis of nitrogen heterocycles are presented. The reactions are catalyzed by chiral copper(II) complexes, and MnO2 is used as
- Zeng, Wei,Chemler, Sherry R.
-
p. 12948 - 12949
(2008/09/17)
-
- A new, simple synthesis of N-tosyl pyrrolidines and piperidines
-
Iodocyclization of unsaturated tosylamides promoted by Oxone oxidation of KI afforded, in good yields, N-tosyl iodopyrrolidines and piperidines. A new, simple method for the conversion of alcohols to tosylamides is presented. Georg Thieme Verlag Stuttgart.
- Marcotullio, Maria Carla,Campagna, Valerio,Sternativo, Silvia,Costantino, Ferdinande,Curini, Massimo
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p. 2760 - 2766
(2008/02/05)
-
- Radical cascade cyclizations and platinum(II)-catalyzed cycloisomerizations of ynamides
-
Ynamides are tested as new partners in radical and organometallic transformations. A radical cascade involving a 5-exo-dig cyclization followed by a 6-endo-trig radical trapping transforms ynamides into hetero-polycyclic compounds such as isoindoles, isoindolinones and pyrido-isoindolones. Various ene-tosylynamides react with platinum(II) chloride and lead to bicyclic nitrogenated heterocycles. This unprecedented and easily operated process can be coupled with a hydrolysis of the intermediate cyclic tosylenamides in a one-pot transformation, which provides cyclobutanones.
- Marion, Frédéric,Coulomb, Julien,Servais, Aurore,Courillon, Christine,Fensterbank, Louis,Malacria, Max
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p. 3856 - 3871
(2007/10/03)
-
- Electrophilic cyclization of N-alkenylamides using?a chloramine-T/I2 system
-
A new protocol for the cyclization of N-alkenylamides using chloramine-T and iodine is described. When N-alkenylsulfonamides are treated with chloramine-T and iodine, three- to six-membered N-heterocycles are obtained with complete stereoselectivity. The method is compatible with the cyclization of the allylbenzamide or allylbenzthioamide to afford an oxazoline or thiazoline derivative, respectively. Mechanistic studies indicate that the chloramine-T/I2 system functions as an effective iodonium species.
- Morino, Yoshinobu,Hidaka, Ikumasa,Oderaotoshi, Yoji,Komatsu, Mitsuo,Minakata, Satoshi
-
p. 12247 - 12251
(2007/10/03)
-
- Platinum dichloride-catalyzed cycloisomerization of ene-ynamides
-
Various ene-tosylynamides react with platinum(II) chloride and lead to bicyclic nitrogenated heterocycles. This unprecedented and easily operated process can be coupled with a hydrolysis of the intermediate cyclic tosylenamides in a one-pot transformation
- Marion, Frederic,Coulomb, Julien,Courillon, Christine,Fensterbank, Louis,Malacria, Max
-
p. 1509 - 1511
(2007/10/03)
-
- Bronsted acid-catalyzed intramolecular hydroamination of protected alkenylamines. Synthesis of pyrrolidines and piperidines.
-
[reaction: see text]. The cyclization of aminoalkenes bearing an electron-withdrawing group on the nitrogen atom was catalyzed by triflic or sulfuric acid in toluene. Pyrrolidines and piperidines were formed in excellent yields. N-phenylanilides also underwent cyclization to form gamma-lactams.
- Schlummer, Bjoern,Hartwig, John F
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p. 1471 - 1474
(2007/10/03)
-
- Acid-catalyzed cyclization of vinylsilanes bearing an amino group. Stereoselective synthesis of pyrrolidines
-
(FORMULA PRESENTED) In the presence of an acid catalyst, vinylsilanes 1 bearing an amino group protected by an electron-withdrawing group were smoothly cyclized to 2-(silylmethyl)pyrrolidines 2. This cyclization was utilized for the stereoselective synthe
- Miura, Katsukiyo,Hondo, Takeshi,Nakagawa, Takahiro,Takahashi, Tatsuyuki,Hosomi, Akira
-
p. 385 - 388
(2007/10/03)
-
- Atom transfer radical cyclisations of activated and unactivated N-allylhaloacetamides and N-homoallylhaloacetamides using chiral and non-chiral copper complexes
-
Activated N-tosyl-2,2,2-trichloroacetamide 6a, N-benzyl-2,2,2-trichloroacetamide 6d, 2,2-dichloroacetamides 6b-c and 6e-f and 2-monohaloacetamides lla-g undergo efficient 5-exo atom transfer radical cyclisations at room temperature mediated by CuCl or CuBr in the presence of tris(N,N-dimethylaminoethylene)amine 3 (trien-Me6). The efficiency and stereoselectivity of these cyclisations was found to be greater than existing published atom transfer procedures based upon CuCl(bipyridine), RuCl2(PPh3)3 and CuCl(TMEDA)2. The product distribution for the cyclisation onto alkyne 11g was found to be solvent dependent. Attempts to make larger ring sizes by endo cyclisation of N-tosylacetamides 19a-c led to a competing 5-exo ipso aromatic substitution into the N-tosyl group followed by re-aromatisation and loss of SO2 to furnish an amidyl radical. Cyclisation of N-homoallylacetamides 25a-d proceeded smoothly to give δ-lactams with a range of catalysts based upon ligands 2 and 26. The stereoselectivity of cyclisation to give γ lactams could be somewhat influenced by using chiral enantiopure copper complexes 28-30 suggesting that the reactions may involve metal-complexed radicals.
- Clark, Andrew J.,De Campo, Floryan,Deeth, Robert J.,Filik, Robert P.,Gatard, Sylvain,Hunt, Nicola A.,Lastecoueres, Dominique,Thomas, Gerard H.,Verlhac, Jean-Baptiste,Wongtap, Hathaichanuk
-
p. 671 - 680
(2007/10/03)
-
- IMDAF Cycloaddition as a Method for the Preparation of Pyrrolophenanthridine Alkaloids
-
Acylation of 5-amino-2-furancarboxylic acid methyl ester with alkenoyl acid chlorides gives 2-amidofurans that undergo intramolecular Diels-Alder cycloadditions. The reactions occur at 165°C in toluene or at 100°C when 4 M ethereal LiClO4 was u
- Padwa, Albert,Dimitroff, Martin,Waterson, Alex G.,Wu, Tianhua
-
p. 3986 - 3997
(2007/10/03)
-
- Synthesis of 2-substituted nitrogen heterocycles using para-toluenesulfonyl iodide in a key step
-
N-Protected aminoalkenes undergo radical addition of tosyl iodide to give β-iodosulfones which can subsequently be induced to cyclise giving 2-substituted pyrrolidines and piperidines. Incorporation of an α-methylbenzyl group at nitrogen leads to a diastereoselective ring closure where the constituent diastereoisomers can be separated readily giving chiral, non-racemic heterocycles.
- Craig,Edwards,Muldoon
-
p. 1441 - 1443
(2007/10/03)
-
- 1,5-Hydrogen transfers from carbon to N-tributyltin substituted nitrogen
-
1,5-H transfers from carbon to N-tributyltin substituted nitrogen proceeded smoothly and were much more efficient than 1,5-H transfers from carbon to ordinary nitrogen. 1,5-Tribuyltin group transfer from carbon to nitrogen and intramolecular addition of an aminyl radical to a nitrile group were also observed for the first time.
- Kim, Sunggak,Yeon, Kyu Man,Yoon, Kwang Sub
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p. 3919 - 3922
(2007/10/03)
-
- Palladium-Catalyzed Cyclization of ω-Olefinic Tosamides. Synthesis of Nonaromatic Nitrogen Heterocycles
-
The cyclization of aliphatic amino olefins to nonaromatic nitrogen heterocycles nas been accomplished by conversion of the amine to the corresponding p-toluenesulfonamide, followed by Pd(II)-catalyzed intramolecular amination of the olefin.The resulting t
- Hegedus, Louis S.,McKearin, James M.
-
p. 2444 - 2451
(2007/10/02)
-