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Atom Transfer Radical Polymerization-Inspired Room Temperature (sp3)C-N Coupling
A simple nonphotochemical procedure is reported for Cu(I)-catalyzed C-N coupling of aliphatic halides with amines and amides. The process is loosely based on the Goldberg reaction but takes place readily at room temperature. It uses Cu(I)Br, a commonly used and inexpensive atom transfer radical polymerization precatalyst, along with the cheap ligand N,N,N′,N″,N″-pentamethyldiethylenetriamine, to activate the R-X bond of the substrate via inner-sphere electron transfer. The procedure brings about productive C-N bond formation between a range of alkyl halide substrates with heterocyclic aromatic amines and amides. The mechanism of the coupling step, which was elucidated through application of computational methods, proceeds via a unique Cu(I) → Cu(II) → Cu(III) → Cu(I) catalytic cycle, involving (a) inner-sphere electron transfer from Cu(I) to the alkyl halide to generate the alkyl radical; (b) successive coordination of the N-nucleophile and the radical to Cu(II); and finally reductive elimination. In the absence of a nucleophile, debrominative homocoupling of the alkyl halide occurs. Control experiments rule out SN-type mechanisms for C-N bond formation.
Coote, Michelle L.,Fung, Alfred. K. K.,Sherburn, Michael S.,Yu, Li-Juan
p. 9723 - 9732
(2021/07/20)

Synthesis of Lactams by Reductive Amination of Carbonyl Derivatives with ω-Amino Fatty Acids under Hydrosilylation Conditions
An efficient method for the preparation of lactams from ω-amino fatty acids under hydrosilylation is described. A variety of lactams such as pyrrolidinones, piperidinones and 2-azepanones were selectively synthesised in moderate to excellent yields (29 examples, up to 95 % isolated yields) with a good functional group tolerance. Notably, no metallic based catalyst was required to perform this transformation.
Tongdee, Satawat,Wei, Duo,Wu, Jiajun,Netkaew, Chakkrit,Darcel, Christophe
supporting information
p. 5536 - 5539
(2021/08/07)

Transition-Metal-Free Reductive Functionalization of Tertiary Carboxamides and Lactams for α-Branched Amine Synthesis
A new method for the synthesis of α-branched amines by reductive functionalization of tertiary carboxamides and lactams is described. The process relies on the efficient and controlled reduction of tertiary amides by a sodium hydride/sodium iodide composite, in situ treatment of the resulting anionic hemiaminal with trimethylsilyl chloride and subsequent coupling with nucleophilic reagents including Grignard reagents and tetrabutylammonium cyanide. The new method exhibits broad functional-group compatibility, operates under transition-metal-free reaction conditions, and is suitable for various synthetic applications on both sub-millimole and on multigram scales.
Chiba, Shunsuke,Dixon, Darren J.,Fan, Dongyang,Ong, Derek Yiren
supporting information
p. 11903 - 11907
(2020/05/22)

Solvent-free iron(III) chloride-catalyzed direct amidation of esters
Amide functional groups are prominent in a broad range of organic compounds with diverse beneficial applications. In this work, we report the synthesis of these functional groups via an iron(iii) chloride-catalyzed direct amidation of esters. The reactions are conducted under solvent-free conditions and found to be compatible with a range of amine and ester substrates generating the desired amides in short reaction times and good to excellent yields at a catalyst loading of 15 mol%.
Mkhonazi, Blessing D.,Shandu, Malibongwe,Tshinavhe, Ronewa,Simelane, Sandile B.,Moshapo, Paseka T.
supporting information

(2020/03/17)

Carbonylative C-C bond activation of aminocyclopropanes using a temporary directing group strategy
Temporary directing groups (TDGs) underpin a range of C-C bond activation methodologies; however, the use of TDGs for the regiocontrolled activation of cyclopropane C-C bonds is underdeveloped. In this report, we show how an unusual ring contraction process can be harnessed for TDG-based carbonylative C-C bond activations of cyclopropanes. The method involves the transient installation of an isocyanate-derived TDG, rather than relying on carbonyl condensation events as used in previous TDG-enabled C-C bond activations.
Wang, Gang-Wei,Sokolova, Olga O.,Young, Tom. A.,Christodoulou, Ektor M. S.,Butts, Craig P.,Bower, John F.
supporting information
p. 19006 - 19011
(2020/11/13)

Palladium-Catalyzed Construction of Quaternary Stereocenters by Enantioselective Arylation of γ-Lactams with Aryl Chlorides and Bromides
Herein, we report the first Pd-catalyzed enantioselective arylation of α-substituted γ-lactams. Two sets of conditions were developed for this transformation, allowing for the use of either aryl chlorides or bromides as electrophiles. Utilizing a highly electron-rich dialkylphosphine ligand we have been able to construct α-quaternary centers in good yields (up to 91 % yield) and high enantioselectivities (up to 97 % ee).
Jette, Carina I.,Geibel, Irina,Bachman, Shoshana,Hayashi, Masaki,Sakurai, Shunya,Shimizu, Hideki,Morgan, Jeremy B.,Stoltz, Brian M.
supporting information
p. 4297 - 4301
(2019/02/27)

Ruthenium-catalyzed synthesis of: N -substituted lactams by acceptorless dehydrogenative coupling of diols with primary amines
Herein, we report the first example of synthesis of N-substituted lactams via an acceptorless dehydrogenative coupling of diols with primary amines in one step, which was enabled by combining Ru3(CO)12 with a hybrid N-heterocyclic carbene-phosphine-phosphine ligand as the catalyst.
Zheng, Yanling,Nie, Xufeng,Long, Yang,Ji, Li,Fu, Haiyan,Zheng, Xueli,Chen, Hua,Li, Ruixiang
supporting information
p. 12384 - 12387
(2019/10/19)

Transition-Metal-Free Deconstructive Lactamization of Piperidines
One of the major challenges in organic synthesis is the activation or deconstructive functionalization of unreactive C(sp3)–C(sp3) bonds, which requires using transition or precious metal catalysts. We present here an alternative: the deconstructive lactamization of piperidines without using transition metal catalysts. To this end, we use 3-alkoxyamino-2-piperidones, which were prepared from piperidines through a dual C(sp3)–H oxidation, as transitory intermediates. Experimental and theoretical studies confirm that this unprecedented lactamization occurs in a tandem manner involving an oxidative deamination of 3-alkoxyamino-2-piperidones to 3-keto-2-piperidones, followed by a regioselective Baeyer–Villiger oxidation to give N-carboxyanhydride intermediates, which finally undergo a spontaneous and concerted decarboxylative intramolecular translactamization.
Romero-Iba?ez, Julio,Cruz-Gregorio, Silvano,Sandoval-Lira, Jacinto,Hernández-Pérez, Julio M.,Quintero, Leticia,Sartillo-Piscil, Fernando
p. 8867 - 8871
(2019/05/28)

Schmidt Reaction of ω-Azido Valeryl Chlorides Followed by Intermolecular Trapping of the Rearrangement Ions: Synthesis of Assoanine and Related Pyrrolophenanthridine Alkaloids
The Schmidt reaction of ω-azido valeryl chlorides in the presence of an additional nucleophile was explored. The arenes, alcohols, and amines were demonstrated as the intermolecular trapping reagents for isocyanate ion and N-acyliminium ion from the Schmidt rearrangement, affording the corresponding products with moderate to excellent yields. Two 2-oxoindoles from the reaction were successfully converted into four natural alkaloids, namely, assoanine, anhydrolycorine, oxoassoanine, and anhydrolycorinone.
DIng, Shao-Lei,Ji, Yang,Su, Yan,Li, Rui,Gu, Peiming
p. 2012 - 2021
(2019/02/14)

C-Alkylation of N-alkylamides with styrenes in air and scale-up using a microwave flow reactor
C-Alkylation of N-alkylamides with styrenes is reported, proceeding in ambient air/moisture to give arylbutanamides and pharmaceutically-relevant scaffolds in excellent mass balance. Various amide and styrene derivatives were tolerated, rapidly affording molecular complexity in a single step; thus highlighting the future utility of this transformation in the synthetic chemistry toolbox. Reaction scalability (up to 65 g h-1 product) was demonstrated using a Microwave Flow reactor, as the first example of a C-alkylation reaction using styrenes in continuous flow.
Barham, Joshua P.,Tamaoki, Souma,Egami, Hiromichi,Ohneda, Noriyuki,Okamoto, Tadashi,Odajima, Hiromichi,Hamashima, Yoshitaka
supporting information
p. 7568 - 7573
(2018/11/02)

Palladium-Catalyzed Hydrocarbonylative C-N Coupling of Alkenes with Amides
An efficient palladium-catalyzed hydrocarbonylative C-N coupling of alkenes with amides has been developed. The reaction was performed via hydrocarbonylation of alkenes, followed by acyl metathesis with amides. Both intermolecular and intramolecular react
Zhou, Xibing,Zhang, Guoying,Gao, Bao,Huang, Hanmin
supporting information
p. 2208 - 2212
(2018/04/30)

Natural α-methylenelactam analogues: Design, synthesis and evaluation of α-alkenyl-γ and δ-lactams as potential antifungal agents against Colletotrichum orbiculare
In our continued efforts to improve the potential utility of the α-methylene-γ-lactone scaffold, 62 new and 59 known natural α-methylenelactam analogues including α-methylene-γ-lactams, α-arylidene-γ and δ-lactams, and 3-arylideneindolin-2-ones were synthesized as the bioisosteric analogues of the α-methylenelactone scaffold. The results of antifungal and cytotoxic activity indicated that among these derivatives compound (E)-1-(2, 6-dichlorobenzyl)-3-(2-fluorobenzylidene) pyrrolidin-2-one (Py51) possessed good selectivity with the highest antifungal activity against Colletotrichum orbiculare with IC50?=?10.4?μM but less cytotoxic activity with IC50?=?141.2?μM (against HepG2 cell line) and 161.2?μM (against human hepatic L02?cell line). Ultrastructural change studies performed by transmission electron microscope showed that Py51 could cause important cell morphological changes in C.?orbiculare, such as plasma membrane detached from cell wall, cell wall thickening, mitochondria disruption, a dramatic increase in vacuolation, and eventually a complete loss in the integrity of organelles. Significantly, mitochondria appeared one of the primary targets, as confirmed by their remarkably aberrant morphological changes. Analysis of structure–activity relationships revealed that incorporation of the aryl group into the α-exo-methylene and the N-benzyl substitution increased the activity. Meanwhile, the α-arylidene-γ-lactams have superiority in selectivity over the 3-arylideneindolin-2-ones. Based on the results, the N-benzyl substituted α-(2-fluorophenyl)-γ-lactam was identified as the most promising natural-based scaffold for further discovering and developing improved crop-protection agents.
Delong, Wang,Lanying, Wang,Yongling, Wu,Shuang, Song,Juntao, Feng,Xing, Zhang
p. 286 - 307
(2017/03/09)

Transition-Metal-Free Amine Oxidation: A Chemoselective Strategy for the Late-Stage Formation of Lactams
A metal-free strategy for the formation of lactams via selective oxidation of cyclic secondary and tertiary amines is described. Molecular iodine facilitates both chemoselective and regioselective oxidation of C-H bonds directly adjacent to a cyclic amine. The mild conditions, functional group tolerance, and substrate scope are demonstrated using a suite of diverse small molecule cyclic amines, including clinically approved drug scaffolds.
Griffiths, Robert J.,Burley, Glenn A.,Talbot, Eric P. A.
supporting information
p. 870 - 873
(2017/02/26)

Palladium(II)-Catalyzed Allylic C H Oxidation of Hindered Substrates Featuring Tunable Selectivity Over Extent of Oxidation
The use of Oxone and a palladium(II) catalyst enables the efficient allylic C H oxidation of sterically hindered α-quaternary lactams which are unreactive under known conditions for similar transformations. This simple, safe, and effective system for C H activation allows for unusual tunable selectivity between a two-electron oxidation to the allylic acetates and a four-electron oxidation to the corresponding enals, with the dominant product depending on the presence or absence of water. The versatile synthetic utility of both the allylic acetate and enal products accessible through this methodology is also demonstrated.
Xing, Xiangyou,O'Connor, Nicholas R.,Stoltz, Brian M.
supporting information
p. 11186 - 11190
(2016/07/06)

Iridium-Catalyzed Single-Step N-Substituted Lactam Synthesis from Lactones and Amines
Catalytic lactam synthesis was achieved directly from lactones and amines using an Ir catalyst. Three sequential transformations - aminolysis of lactone, N-alkylation of amine with hydroxyamide, and intramolecular transamidation of aminoamide - afforded the corresponding N-substituted lactams. (Figure Presented).
Kim, Kicheol,Hong, Soon Hyeok
supporting information
p. 4152 - 4156
(2015/05/04)

Palladium-catalyzed C - O hydrogenolysis in γ-hydroxy γ-lactams as an efficient approach to 5-alkyl(aryl)pyrrolidin-2-ones
5-R-Pyrrolidin-2-ones were synthesized by Pd/Sibunit-catalyzed C - O hydrogenolysis of 5-R-5-hydroxypyrrolidin-2-ones with molecular hydrogen.
Turova,Berezhnaya,Starodubtseva,Ferapontov,Vinogradov
p. 859 - 863
(2015/12/24)

Asymmetric synthesis and evaluation of α-quaternary chiral lactam derivatives as novel anticancer agents
Asymmetric synthesis of α-quaternary chiral lactam derivatives as novel anticancer agents and evaluation of their cytotoxic potentials and spectrums are reported. Among the developed lactam derivatives, the most active new compounds (S)-4m and (S)-4n synthesized via asymmetric phase-transfer catalytic alkylation in very high optical yields (98 % ee) show promising in vitro anticancer activities with low micromolar IC50 values against colon, uterus, lung, and breast human cancer cells.
Lee, Hwanhyuk,Hwang, Su Jung,Jung, Jisung,Hong, Suckchang,Lee, Myungmo,Park, Hyeung-Geun,Lee, Hyo-Jong,Park, Yohan
p. 1264 - 1270
(2015/10/05)

The efficient preparation of α, β, γ-lactam derivatives
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Lee, Mi-Jee,Jang, Ji-Sung,Ahn, Chuljin
p. 855 - 858
(2014/02/14)

SmI2-Mediated intermolecular coupling of γ-lactam N-α-radicals with activated alkenes: Asymmetric synthesis of 11-hydroxylated analogues of the lead compounds CP-734432 and PF-04475270
We report, for the first time, the synthesis of 8-aza-analogues of PGE 2. The SmI2-mediated cross coupling reactions of γ-lactam-hemiaminal 9, lactam 2-pyridyl sulfide 17, and lactam 2-pyridyl sulfone 18 with activated alkenes/alkyne
Hu, Kong-Zhen,Ma, Jie,Qiu, Shi,Zheng, Xiao,Huang, Pei-Qiang
p. 1790 - 1801
(2013/03/28)

A one-pot selective synthesis of N-Boc protected secondary amines: Tandem direct reductive amination/N-Boc protection
A one-pot tandem direct reductive amination of aldehydes with primary amines resulting in N-Boc secondary amines using a (Boc)2O/sodium triacetoxyborohydride (STAB) system is reported. The tandem procedure is efficient, selective, and versatile, giving excellent yields of N-Boc protected secondary amines even in those cases where the products are prone to intramolecular lactamization.
Neelarapu, Raghupathi,Petukhov, Pavel A.
scheme or table
p. 7056 - 7062
(2012/08/28)

Rh-catalyzed intramolecular debenzylative cyclization of amines. Butyrolactams from benzylamines having a chloroacetylene moiety
When benzylamines having a chloroacetylene moiety were heated in wet toluene with a catalytic amount of rhodium trifluoroacetate dimer, intramolecular debenzylative cyclization took place to give butyrolactams. This method is a new entry to selective debenzylation of amines.
Oh, Yun Taek,Senda, Kousuke,Hata, Takeshi,Urabe, Hirokazu
p. 2458 - 2461
(2011/05/16)

Catalytic, asymmetric vinylogous Mukaiyama aldol reactions of pyrrole- and furan-based dienoxy silanes: How the diene heteroatom impacts stereocontrol
Denmark's chiral bisphosphoramide/silicon tetrachloride system performs as an excellent Lewis base-Lewis acid catalyst for the vinylogous Mukaiyama aldol reaction of pyrrole- and furan-based dienoxy silanes with aromatic and heteroaromatic aldehydes. This asymmetric methodology provides a powerful synthetic entry to a variety of d-hydroxylated g-butenolide-type frameworks with high efficiency and valuable margins of regio-, diastereo-, and enantioselectivity. Notably, the nature of the heteroatom within the vinylogous dienoxy silane donor heavily impacts the diastereocontrol, with syn-configured aldol adducts emerging from pyrroles bearing electron- withdrawing N-protecting groups (Boc, Ts, and Cbz) and anti-configured adducts prevailing when furan- or N-alkyl/alkenylpyrrole donors are involved.
Curti, Claudio,Ranieri, Beatrice,Battistini, Lucia,Rassu, Gloria,Zambrano, Vincenzo,Pelosi, Giorgio,Casiraghi, Giovanni,Zanardi, Franca
supporting information; experimental part
p. 2011 - 2022
(2010/11/17)

NHC-Catalyzed intramolecular redox amidation for the synthesis of functionalized lactams
A very efficient NHC-catalyzed lactamization reaction is reported. For most cases, the ring expansion reaction proceeds to cleanly furnish five- and six-membered N-Ts and N-Bn lactams, without the need for further purification. Evidence is presented suggesting a dual role for the stoichiometric base: (1) deprotonation of the triazolium precatalyst and (2) activation of the nitrogen leaving group through hydrogen bonding.
Thai, Karen,Wang, Li,Dudding, Travis,Bilodeau, Francois,Gravel, Michel
p. 5708 - 5711
(2011/03/19)

Synthesis of biobased N-methylpyrrolidone by one-pot cyclization and methylation of γ-aminobutyric acid
N-Methylpyrrolidone (NMP) is an industrial solvent that is currently based on fossil resources. In order to prepare it in a biobased way, the possibility to synthesize NMP from γ-aminobutyric acid (GABA) was investigated, since GABA can be obtained from glutamic acid, an amino acid that is present in many plant proteins. Cyclization of GABA to 2-pyrrolidone and subsequent methylation of 2-pyrrolidone to NMP was achieved in a one-pot procedure, using methanol as the methylating agent and a halogen salt (i.e. ammonium bromide) as a catalyst. A selectivity above 90% was achieved, as well as a high conversion. Methylation of 2-pyrrolidone could also be done with dimethyl carbonate, but then the selectivity for NMP was less (67%).
Lammens, Tijs M.,Franssen, Maurice C. R.,Scott, Elinor L.,Sanders, Johan P. M.
scheme or table
p. 1430 - 1436
(2010/09/05)

Iron-catalyzed C-C bond formation at α-position of aliphatic amines via C-H bond activation through 1,5-hydrogen transfer
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Yoshikai, Naohiko,Mieczkowski, Adam,Matsumoto, Arimasa,Ilies, Laurean,Nakamura, Eiichi
scheme or table
p. 5568 - 5569
(2010/06/19)

Triton B-mediated mild, convenient, and efficient method for the selective alkylation of cyclic secondary amines and thiols
Alkylation of cyclic secondary amines, thiols, and pyridazinones has been demonstrated with alkyl halides using Triton B as base and reaction medium.
Meshram,Reddy, B. Chennakesava,Goud, P. Ramesh
experimental part
p. 2297 - 2303
(2009/12/01)

Palladium-catalysed enantioselective α-hydroxylation of β-ketoesters
Highly enantioselective α-hydroxylation of cyclic and acyclic 1,3-ketoesters can be achieved with up to 98% ee using a dicationic palladium(ii) catalyst and dimethyldioxirane as oxidant.
Smith, Alexander M.R.,Billen, Denis,Hii, King Kuok
supporting information; experimental part
p. 3925 - 3927
(2010/01/06)

One-carbon ring expansion of azetidines via ammonium ylide [1,2]-shifts: A simple route to substituted pyrrolidines
Simple N-substituted azetidines were heated with diazocarbonyl compounds in the presence of catalytic Cu(acac)2 to furnish substituted pyrrolidines via Stevens [1,2]-shift. In all but two examples, complete selectivity was seen for ring expansion rather than migration of the other exocyclic group on the azetidinium nitrogen. The two exceptions, observed with ylides substituted with two carbonyl groups and lacking a stabilizing group at the 2-position of the azetidine, underwent exocyclic benzyl migration in preference to ring expansion.
Bott, Tina M.,Vanecko, John A.,West
body text
p. 2832 - 2836
(2009/08/15)

Fast, acid-free, and selective lactamization of lactones in ionic liquids
(Chemical Equation Presented) A fast and acid-free one-pot 0.2-30 mmol microwave methodology for direct ionic liquid-mediated preparation of lactams from lactones and primary amines has been developed. The protocol was investigated with a wide range of primary amines and a handful of lactones, including substrates with acid-sensitive substituents. Both γ-lactams and δ-lactams were, despite the complete absence of a Bronsted acid, obtained in useful to excellent yields after only 35 min of microwave processing.
Orrling, Kristina M.,Wu, Xiongyu,Russo, Francesco,Larhed, Mats
supporting information; experimental part
p. 8627 - 8630
(2009/04/11)

N-benzyl-5-hydroxy-3-pyrrolidin-2-one by hydrogen peroxide oxidation of N-benzyl-3-phenylseleno-2-pyrrolidinone
Using the known peroxide oxidation of N-benzyl-3-phenylseleno-2- pyrrolidinone with 30% hydrogen peroxide at -5°C after 3.5 h, we prepared the expected N-benzyl-3-pyrrolin-2-one. However, reaction with 30% hydrogen peroxide for 12 h (-5°C→ambient) gave the unexpected product N-benzyl-5-hydroxy-3-pyrrolidin-2-one in 84% isolated yield. This procedure is a new synthetic route to N-benzyl-5-hydroxy-3-pyrrolidin-2-one. Copyright Taylor & Francis Group, LLC.
Mun, JiYoung,Smith, Michael B.
p. 813 - 819
(2007/10/03)

Acid-catalyzed rearrangement of 1-benzyl-2-methyl-3-piperidone to 1-benzyl-2-acetylpyrrolidine
We report that 1-benzyl-2-methyl-3-piperidone, conveniently prepared from 3-hydroxy-2-methylpyridine, undergoes rearrangement to 1-benzyl-2-acetylpyrrolidine in aqueous 6 N HCl at reflux. Studies showing that the 2,2-dimethyl analog is inert under the same conditions support a mechanism of reversible tautomeric equilibria via ring-opened intermediates, one of which was independently synthesized and shown to be a kinetically competent intermediate to product.
Zhao, Shengyin,Jeon, Heung-Bae,Nadkarni, Durgesh V.,Sayre, Lawrence M.
p. 6361 - 6369
(2007/10/03)

Indole cleavage with mebhydroline by sodium periodate - Part 2. Mechanism of the dilactam formation
The γ-carbolines 1a-d reacted with periodate by loss of one carbon - without available precursors - to the eight-membered dilactams 3a-c and the amino acid 9d. As possible intermediates of an indole cleavage α-aminoketones as models were examined. While the oxidation of chain-formed 13 afforded only a small amount of C-lost amide 23, the cyclic species 24 and 32 gave rise to considerably higher yields of the corresponding lactams 29 and 36. From the benzazepinone 32 with Hg(II)-EDTA the intermediate product 43, containing all genuine C-atoms, was formed, which could quantitatively cleaved by periodate to the lactam 36 and formic acid. This mechanism can be transferred to the reactions of the γ-carbolines 1a-d.
Moehrle,Rohn,Westle
p. 391 - 399
(2007/10/03)

Generation and cyclization of unsaturated carbamoyl radicals derived from S-4-pentynyl carbamothioates under tin-free conditions
The radical reaction of benzenethiol with S-4-pentynyl carbamothioates provides a valuable protocol for the tin-free generation of carbamoyl radicals, which arise from intramolecular substitution at sulfur by the initial sulfanylvinyl radicals. This procedure can be usefully employed to achieve N-benzylcarbamoyl radical 5-exo and 4-exo cyclizations leading, respectively, to pyrrolidinones and azetidinones, although, for the latter, it seems of lesser utility. Novel evidence is presented that. N-tosyl-substituted carbamoyl radicals display a peculiar tendency to yield the corresponding isocyanate by β-elimination of the tosyl radical.
Benati, Luisa,Bencivenni, Giorgio,Leardini, Rino,Minozzi, Matteo,Nanni, Daniele,Scialpi, Rosanna,Spagnolo, Piero,Zanardi, Giuseppe
p. 3192 - 3197
(2007/10/03)

Synthesis of functionalised azecine and azonine derivatives via an enolate assisted aza Claisen rearrangement
This paper describes the synthesis of functionalised azecine and azonine derivatives incorporating the adrenaline motif. In a key step, an enolate assisted aza Claisen rearrangement was employed to interconvert from 6- and 5-membered heterocycles to their corresponding 10- and 9-membered lactams.
Bremner, John B.,Perkins, David F.
p. 2659 - 2665
(2007/10/03)

Ring-expanding reaction of cyclopropyl amides with triphenylphosphine and carbon tetrahalide
We succeeded in activating cyclopropyl amides (monoactivated cyclopropane) through the corresponding imidoyl halides prepared in situ in the presence of 2 equiv of PPh3 and 1 equiv of CX4, and the ring-expanding products (N-substituted pyrrolidin-2-ones) were obtained in good yields. The reaction mechanism was investigated on the basis of oxygen-18 tracer experiment.
Yang, Yong-Hua,Shi, Min
p. 8645 - 8648
(2007/10/03)

Investigations into the mechanism of lactamization of lactones yielding in a novel route to biologically active tryptamine derivatives
The mechanism of lactamization of corresponding lactones was investigated by means of gas chromatography and synthesis of possible intermediates as references. Lactones react with amines via the amino acid with subsequent elimination of water to the corresponding lactams. In the first step, also hydroxyamides are in equilibrium with the lactones and amines, respectively, which are not able to form the amide though. This mechanism opens a new approach for the synthesis of Nβ-disubstituted tryptamines.
Decker, Michael,Nguyen, Thi Thanh Huyen,Lehmann, Jochen
p. 4567 - 4578
(2007/10/03)

N-Alkylation of anilines, carboxamides and several nitrogen heterocycles using CsF-Celite/alkyl halides/CH3CN combination
It has been found that the N-alkylation of aniline, carboxamides and heterocyclic compounds bearing an acidic hydrogen atom attached to nitrogen can be accomplished with alkyl halides in acetonitrile and cesium fluoride-celite employed as a solid base. In this manner, pyrrole, indole, pyrazole, imidazole, benzimidazole, carbazole, phthalimide, indazole, indoline, 2-pyrrolidinone, piperidine and 1,2,4-triazole can be successfully alkylated. The procedure is convenient, efficient and generally gives rise to the N-alkylated product exclusively.
Hayat, Safdar,Atta-Ur-Rahman,Iqbal Choudhary,Khan, Khalid Mohammed,Schumann, Wilhelm,Bayer, Ernst
p. 9951 - 9957
(2007/10/03)

Nitrogen-philic cyclization of acyl radicals onto N = C bond. New synthesis of 2-pyrrolidinones by radical carbonylation/annulation method [17]
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Ryu,Matsu,Minakata,Komatsu
p. 5838 - 5839
(2007/10/03)

Reaction of β-, γ-, and δ-chloroalkanamides with potassium tert-butoxide in tetrahydrofuran: Elimination, and lactamization
γ- and δ-Chloroalkanamides were found to undergo lactamization readily when treated with potassium tert-butoxide in tetrahydrofuran. Raising the reaction temperature may encourage SN2 displacement reaction. On the other hand β-chloroalkanamides only undergo elimination, followed by dimerization and trimerization of the acrylamide initially formed.
Wang, Eng Chi,Lin, Huey-Jen
p. 481 - 489
(2007/10/03)

Generation of 1-Amidoalkyl Radicals from N-Protected Amino Acids: An Alternative to the Barton Decarboxylation Procedure
An alternative method to the Barton decarboxylation procedure of N-protected amino acids is presented. The carboxylic acids are transformed into stable phenylselenoesters. Upon standard radical reaction conditions, they generate acyl radicals which undergo a very fast decarbonylation reaction to N-protected 1-aminoalkyl radicals. The decarbonylated radicals are trapped reductively and by intermolecular additions to olefins.
Stojanovic, Aleksandar,Renaud, Philippe
p. 181 - 182
(2007/10/03)

Reductive O- and N-alkylations. Alternative catalytic methods to nucleophilic substitution
Different amides have been selectively mono-N-alkylated using catalytic heterogeneous palladium and carbonyl compounds as alkylating agents. The same salt free method has been applied to the synthesis of ethers from alcohols. Reaction parameters have been studied in detail and a mechanism is proposed.
Fache, Fabienne,Bethmont, Valerie,Jacquot, Laurent,Lemaire, Marc
p. 231 - 238
(2007/10/03)

Preparation and epoxidation of conjugated lactams: Influence of ring size on epoxidation
α,β-Epoxy-lactams can be prepared from conjugated lactams by treatment with m-chloroperoxybenzoic acid. Good yields are obtained, however, only with 2-pyrrolidinone derivatives. The yield of epoxy-lactam diminishes dramatically as the size of the lactam ring increases.
Li,Smith
p. 1265 - 1275
(2007/10/02)

Extension of the Eschweiler-Clarke procedure to the N-alkylation of amides
The selective N-alkylation of amides (cyclic or acyclic) under hydrogen is reported using aldehydes or ketones as alkylating agents and Pd/C/Na2SO4 as catalyst. Good isolated yields are obtained (81% to 98%).
Fache, Fabienne,Jacquot, Laurent,Lemaire, Marc
p. 3313 - 3314
(2007/10/02)

Synthesis of Pyrrolidines and Pyrrolidinones by the Rhodium Complex Catalyzed Cyclization of Unsaturated Amines
N-Allylic arylamines react with carbon monoxide, sodium borohydride, 2-propanol, and catalytic amounts of the zwitterionic complex η6-C6H6BPh3-Rh(COD)+ (1), to form pyrrolidines as the main products in most cases.Pyrrolidinones result from N-allylic alkylamines.An alternate route to the lactams from N-allylic alkylamines involves synthesis gas instead of CO/NaBH4, together with the dual catalytic system 1/2.Complementary to the N-allylic arylamine route to pyrrolidines with NaBH4 and 1 is the use of synthesis gas, 1, and 1,4-bis(diphenylphosphino)butane.
Zhou, Jian-Qiang,Alper, Howard
p. 3328 - 3331
(2007/10/02)

Cyclic amine derivatives, pharmaceutical compositions containing these compounds and methods for preparing them
Disclosed are new cyclic amine derivatives of the formula I STR1 wherein the substituents are defined in the specification. These compounds are useful as for treating sinus tachycardia.
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(2008/06/13)

Synthesis of hexahydroindol-6-ones by reaction of 2-methylthiopyrrolinium salts with Nazarov reagents
The title compounds 6-8 were prepared by variations of a route commencing with base-promoted condensation of N-substituted 2-methylthio-Δ1-pyrrolinium iodides 2 with Nazarov and related reagents, followed by further manipulation of substituted enamines 11-14.
Michael,Zwane
p. 4755 - 4758
(2007/10/02)

Mechanism of Solid/Liquid Phase-transfer Catalysis in the Presence of Potassium Carbonate: Alkylation of Pyrrolodin-2-one
Solid potassium carbonate is the base chosen for the solid/liquid phase-transfer catalysed benzylation of pyrrolidin-2-one.A kinetic and mechanistic study has been carried out in which the effects of various parameters on the behaviour of the system have been evaluated.It was concluded that this reaction proceeds via the 'interfacial mechanism' and no extraction of the carbonate anion is taking place.In addition, the essential role of water in this process was found to be similar to its function in the 'extraction mechanism.'
Sasson, Yoel,Bilman, Nissim
p. 2029 - 2034
(2007/10/02)

(Trimethylsilyl)ethoxyacetylene. An Effective Reagent for Mild Dehydrative Condensation of Carboxylic Acids and H-Acidic Materials
(Trimethylsilyl)ethoxyacetylene, a stable and easy to handle dehydrating reagent, is quite effective for the title condensation to prepare ester-, lactone-, lactam-, and peptide-linkages under mild conditions.
Kita, Yasuyuki,Akai, Shuji,Yamamoto, Miki,Taniguchi, Miyako,Tamura, Yasumitsu
p. 334 - 337
(2007/10/02)

EFFICIENT SYNTHESIS OF N-SUBSTITUTED LACTAMS FROM (N-ARYLSULFONYLOXY)AMINES AND CYCLIC KETONES
A new method is reported for the direct preparation of N-substituted lactams from cycloalkanones.N-(p-nitrobenzenesulfonoxyl) methylamine 1a (CH3NH-OSO2C6H4NO2) was reacted with a series of cycloalkanones to give good yields of N-methyl lactams.An addition-rearrangement pathway accounts for the ring-expanded lactam products.A series of N-alkyl-N-arylsulfonoxyl amines were generated in situ and reacted with cyclobutanone to give N-alkyl pyrrolidinones in high yields.
Hoffman, Robert V.,Salvador, James M.
p. 4207 - 4210
(2007/10/02)

SIMPLE METHODS FOR THE N-ALKYLATION OF LACTAMS
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Kramarova, E. P.,Shipov, A. G.,Orlova, N. A.,Artamkina, O. B.,Belavin, I. Yu.,Baukov, Yu. I.
p. 970 - 979
(2007/10/02)