- Regiodivergent and Stereospecific Aziridine Opening by Copper-Catalyzed Addition of Silicon Grignard Reagents
-
A stereospecific ring opening of various 2-aryl-substituted aziridines with silicon Grignard reagents under copper catalysis is reported. The regiochemical outcome is governed by the steric demand of the silicon nucleophile. The LiCl introduced with the m
- Yi, Hong,Oestreich, Martin
-
supporting information
p. 6505 - 6507
(2019/04/30)
-
- Organocatalytic nitrenoid transfer: Metal-free selective intermolecular C(sp3)-H amination catalyzed by an iminium salt
-
This report details the first organocatalytic method for nitrenoid transfer and its application to intermolecular, site-selective C(sp3)-H amination. The method utilizes a trifluoromethyl iminium salt as the catalyst, iminoiodinanes as the nitrogen source, and substrate as the limiting reagent. Activated, benzylic, and aliphatic substrates can all be selectively functionalized in yields up to 87%. A mechanistic proposal for the observed reactivity supported by experimental evidence invokes the intermediacy of a diaziridinium salt or related organic nitrenoid, species that have not been previously explored for the purpose of C-H amination. Finally, examples of late-stage functionalization of complex molecules highlight the selectivity and potential utility of this catalytic method in synthesis.
- Combee, Logan A.,Raya, Balaram,Wang, Daoyong,Hilinski, Michael K.
-
p. 935 - 939
(2018/02/07)
-
- Branched Amine Synthesis via Aziridine or Azetidine Opening with Organotrifluoroborates by Cooperative Br?nsted/Lewis Acid Catalysis: An Acid-Dependent Divergent Mechanism
-
A practical catalytic method to synthesize β,β- and γ,γ-substituted amines by opening aziridines and azetidines, respectively, using alkenyl, alkynyl, or aryl/heteroaryl trifluoroborate salts is described. This reaction features simple open-flask reaction conditions, the use of transition-metal-free catalysis, complete regioselectivity, and high diastereoselectivity. Preliminary mechanistic studies suggest that carbocation formation is disfavored. Stereoretentive addition is favored with Br?nsted acid present, while stereoinversion is favored in its absence, indicating divergent mechanisms.
- Nguyen, Truong N.,May, Jeremy A.
-
p. 3618 - 3621
(2018/06/26)
-
- Alkene functionalization for the stereospecific synthesis of substituted aziridines by visible-light photoredox catalysis
-
A novel strategy involving visible-light-induced functionalization of alkenes for the synthesis of substituted aziridines was developed. The readily prepared N-protected 1-aminopyridinium salts were used for the generation of N-centered radicals. This approach allowed the synthesis of aziridines bearing various functional groups with excellent diastereoselectivity under mild conditions. Moreover, this protocol was successfully applied to prepare structurally diverse nitrogen-containing frameworks.
- Yu, Wan-Lei,Chen, Jian-Qiang,Wei, Yun-Long,Wang, Zhu-Yin,Xu, Peng-Fei
-
p. 1948 - 1951
(2018/03/01)
-
- Grafting of copper(II) Schiff base complex on functionalized multi-wall carbon nanotubes: Synthesis, characterization and catalytic aziridination of olefins
-
In this study, hydroxyl functionalized copper(II) Schiff-base; [Cu((OH)2-salophen)], [(OH)2-salophen] = (N,N-bis(4-hydroxysalicylidene) phenylene-1,2-diamine); has been covalently anchored on modified multi-wall carbon nanotubes (MWN
- Bazarganipour, Mehdi,Salavati-Niasari, Masoud
-
-
- Syntheses of a novel fluorinated trisphosphinoborate ligand and its copper and silver complexes. Catalytic activity toward nitrene transfer reactions
-
A novel fluorinated ligand, the anionic PhB(CH2P(p-CF 3C6H4)2)3 (PhBP 3 p-CF3Ph), has been synthesized and characterized, as well as its corresponding thallium, copper
- Arenas, Ismael,Fuentes, M. Angeles,Alvarez, Eleuterio,Diaz, Yolanda,Caballero, Ana,Castillon, Sergio,Perez, Pedro J.
-
p. 3991 - 3999
(2014/05/06)
-
- Metal-free aziridination of styrene derivatives with iminoiodinane catalyzed by a combination of iodine and ammonium iodide
-
The metal-free catalytic aziridination of styrene derivatives with N-tosyliminophenyliodinane (PhI=NTs) in the presence of a combination of I 2 and tetrabutylammonium iodide (TBAI) is reported. In situ generated TBAI3 from I2/s
- Kiyokawa, Kensuke,Kosaka, Tomoki,Minakata, Satoshi
-
supporting information
p. 4858 - 4861
(2013/10/08)
-
- Nanocrystalline zinc peroxide mediated unprecedented nitrene transfer: An expeditious access to N-tosylaziridines
-
An unprecedented zinc peroxide (ZnO2) assisted synthetic strategy is reported for the synthesis of N-tosylaziridines from alkenes by using N-tosyliminotriphenylphosphorane (Ph3PNTs) as a nitrene transfer reagent under mild reaction conditions. The reaction of zinc peroxide with Ph3PNTs yielded a zinc oxaziridine intermediate which subsequently reacts with alkenes to give corresponding N-tosylaziridines in high to excellent yields. The Royal Society of Chemistry 2013.
- Verma, Sanny,Jain, Suman L.
-
p. 19830 - 19833
(2013/11/06)
-
- Nickel-catalyzed negishi alkylations of styrenyl aziridines
-
A nickel-catalyzed cross-coupling reaction between N-sulfonyl aziridines and organozinc reagents is reported. The catalytic system comprises an inexpensive and air-stable Ni(II) source and dimethyl fumarate as ligand. Regioselective synthesis of β-substituted amines is possible under mild and functional-group-tolerant conditions. The stereoselectivity of the reaction is consistent with a stereoconvergent mechanism wherein the sulfonamide directs C-C bond formation.
- Huang, Chung-Yang,Doyle, Abigail G.
-
supporting information; experimental part
p. 9541 - 9544
(2012/07/14)
-
- Sulfur ylide promoted synthesis of N-protected aziridines: A combined experimental and computational approach
-
A range of N-protected aziridines [N-Tosyl (N-Ts), N-2- trimethylsilylethanesulfonamide (N-SES), N-tertbutoxycarbonylamido (N-Boc), and N-o-nitrobenzenesulfonamide (oNs)] were prepared in moderate to good yield and with high enantiomeric excess of both isomers starting from N-protected imines, using a sulfonium salt derived from Eliel's oxathiane. The diastereoselectivities of the reactions are influenced by the imine N-protecting group, the imine substituent, and the sulfide structure. An unusual cis selectivity was observed in the formation of N-tosyl-2-phenyl-3-tert- butylaziridine and N-o-trimethylsilylethanesulfonamide-2-phenyl-3-tert- butylaziridine, which was explained by using computational models. The analysis suggests that betaine formation in the case of N-tosyl-tert-butylaldimine aziridination using oxathiane benzyl sulfonium ylide 1′ is reversible and that the selectivity is determined at the rotation step, which is unusual for semistabilized ylide aziridination. We have shown herein that the steric bulk of an imine substituent, in combination with a sterically demanding sulfonium ylide, can also affect the reversibility of the reaction. This is the first example of this sort involving aziridinations using semistabilized ylides.
- Dokli, Irena,Matanovic, Ivana,Hamersak, Zdenko
-
scheme or table
p. 11744 - 11752
(2010/11/18)
-
- Enhancing the solubility for hypervalent ortho-sulfonyl iodine compounds
-
The synthesis and characterization of new hypervalent iodine reagents ArINTs (2a), ArIO (3a), and ArIO2 (4a) (Ar=2-tert-butylsulfonyl-5- tert-butylphenyl) are described. These reagents are compared to previously reported analogous set of reagen
- Meprathu, Bindu V.,Protasiewicz, John D.
-
experimental part
p. 5768 - 5774
(2010/10/01)
-
- Syntheses of acetonitrile ligated copper complexes with perfluoroalkoxy aluminate as counter anion and their catalytic application for olefin aziridination
-
Acetonitrile ligated copper complexes with perfluoroalkoxy aluminate Al {OC (CF3)3}4- as weakly coordinating counter anion are successfully synthesized. Aziridination of various olefins with PhINTs catalyzed by
- Li, Yang,Diebl, Bernd,Raith, Alexander,Kühn, Fritz E.
-
supporting information; body text
p. 5954 - 5956
(2009/04/11)
-
- Cobalt-catalyzed efficient aziridination of alkenes
-
(Chemical Equation Presented) Cobalt porphyrins are capable of catalyzing the aziridination of alkenes with bromamine-T as the nitrene source. Among cobalt complexes of different porphyrins, Co(TDCIPP) is an effective catalyst that can aziridinate a wide
- Gao, Guang-Yao,Harden, Jeremiah D.,Zhang, X. Peter
-
p. 3191 - 3193
(2007/10/03)
-
- Iron(III) porphyrin catalyzed aziridination of alkenes with bromamine-T as nitrene source
-
Equation presented. Iron(III) porphyrin complexes Fe(Por)Cl are effective catalysts for aziridination of alkenes using bromamine-T as the nitrene source. The catalytic system can operate under mild conditions with alkenes as limiting reagents. The aziridi
- Vyas, Renu,Gao, Guang-Yao,Harden, Jeremiah D.,Zhang, X. Peter
-
p. 1907 - 1910
(2007/10/03)
-
- Efficient Aziridination of Olefins Catalyzed by a Unique Disilver(I) Compound
-
A unique disilver(I) compound is an efficient catalyst for aziridination of olefins. Copyright
- Cui, Yong,He, Chuan
-
p. 16202 - 16203
(2007/10/03)
-
- Microencapsulated Cu(acac)2: A recoverable and reusable polymer-supported copper catalyst for aziridination of olefins
-
Microencapsulated copper(II) acetylacetonate was prepared and used in the aziridination of alkenes employing [N-(p-tolylsulfonyl)imino]phenyliodinane (PhI=NTs) as the nitrogen source. Microencapsulated copper(II) acetylacetonate [MC-Cu(acac)2] catalyst was reused for several cycles with consistent activity.
- Lakshmi Kantam,Kavita,Neeraja,Haritha,Chaudhuri,Dehury
-
p. 9029 - 9032
(2007/10/03)
-
- Additions of stabilised and semi-stabilised sulfur ylides to tosyl protected imines: Are they under kinetic or thermodynamic control?
-
Sulfur ylides react with imines, via betaines, to give aziridines. We sought to determine whether betaine formation was reversible in reactions of benzyl-, amide- and ester-stabilised ylides by carrying out cross-over experiments. Thus, the intermediate betaines were generated independently from the corresponding sulfonium salt in the presence of a more reactive imine (p-nitrobenzaldimine). It was found that no incorporation of the more reactive imine was observed in reactions with the benzyl-stabilised ylide, whilst >80% incorporation of the p-nitrobenzaldimine was observed from the ester- and amide-stabilised ylides. These results indicate that benzyl-stabilised ylides react irreversibly with imines but ester- and amide-stabilised react reversibly. Thus, the stereocontrolling step of the process is dependent on the type of ylide employed and the results are used to account for the different diastereoselectivities observed with the different ylides.
- Aggarwal, Varinder K.,Charmant, Jonathan P.H.,Ciampi, Cinzia,Hornby, Jonathan M.,O'Brien, Christopher J.,Hynd, George,Parsons, Richard
-
p. 3159 - 3166
(2007/10/03)
-
- Aziridination of alkenes and amidation of alkanes by bis(tosylimido)ruthenium(VI) porphyrins. A mechanistic study
-
Bis(tosylimido)ruthenium(VI) porphyrins, [Ru(VI)(Por)(NTs)2] (Por = TPP, TTP, 4-C1-TPP, 4-MeOTPP, OEP), were prepared in 60-74% yields by treatment of [Ru(II)(Por)(CO)(MeOH)] with (N-(p-tolylsulfonyl)- imino)phenyliodinane (PhI=NTS) in dichloromethane. In dichloromethane containing pyrazole, they reacted with alkenes or alkanes to give tosylamidoruthenium(IV) porphyrins, [Ru(IV)(Por)(NHTs)(pz)], in about 75% yields. The reactions of [Ru(VI)(TPP)(NTs)2] and [Ru(VI)(OEP)(NTs)2] with styrene, para-substituted styrenes, norbornene, cyclooctene, and β- methylstyrene afforded the corresponding N-tosylaziridines in 66-85% yields. The aziridination of cis-stilbene and cis-β-methylstyrene by [Ru(VI)(Por)(NTs)2] is nonstereospecific with a partial loss of the alkene stereochemistry. Kinetic studies on the reactions between [Ru(VI)(TPP)(NTs)2] and 16 alkenes (cyclooctene, norbornene, 2,3-dimethyl-2- butene, styrene, para-substituted styrenes, α and β-methylstyrene, and α- and β-deuteriostyrene) gave the second-order rate constants (k2) ranging from (1.60 ± 0.06) x 10-3 to (90 ± 4) x 10-3 dm3 mo1-1 s-1 at 298 K. The slope of the linear plot of log k2 vs E(l/2) for eight representative alkenes was found to be -1.7 V-1. In the case of para-substituted styrenes, linear correlation between log k(R) (k(R) = relative rate) and σ+ gives a ρ+ value as small as -1.1. However, the effect of para substituents on k(R) can be best accounted for by considering both the polar and spin delocalization effect. Measurements on the secondary deuterium isotope effect revealed that only the β-carbon atom of styrene experienced a significant change in its hybridization in reaching the transition state. All these are consistent with rate-determining formation of a carboradical intermediate. The reactions of [Ru(VI)(TPP)(NTs)2] and [Ru(VI-) (OEP)(NTs)2] with adamantane, cyclohexene, ethylbenzene, and cumene resulted in tosylamidation of these hydrocarbons and afforded the corresponding amides in 52-88% yields. For cyclohexane and toluene, the tosylamidation products were formed in poor yields (ca. 10%). Kinetic studies on the reactions between [Ru(VI-) (TPP)(NTs)2] and nine hydrocarbons (cumene, ethylbenzene, cyclohexene, and para-substituted ethylbenzenes) gave the second-order rate constants (k2) in the range of (0.330 ± 0.008) x 10-3 to (16.5 ± 0.3) x 10-3 dm3 mol-1 s-1. These reactions exhibit a large primary deuterium isotope effect, with a k(H)/k(D) ratio of 11 for the tosylamidation of ethylbenzene. In the case of para-substituted ethylbenzenes, both electron-donating and -withdrawing substituents moderately promote the reaction. There is an excellent linear correlation between log k(R) and a related carboradical parameter. On the basis of these observations, a mechanism involving the rate-limiting formation of a carboradical intermediate is postulated.
- Au, Sze-Man,Huang, Jie-Sheng,Yu, Wing-Yiu,Fung, Wai-Hong,Che, Chi-Ming
-
p. 9120 - 9132
(2007/10/03)
-
- Catalytic asymmetric heterogeneous aziridination of alkenes using zeolite CuHY with [N-(p-tolylsulfonyl)imino]phenyliodinane as nitrene donor
-
Copper-exchanged zeolite Y (CuHY) is found to be a highly effective heterogeneous catalyst for the aziridination of alkenes using [N-(p-tolylsulfonyl)imino]phenyliodinane (PhI=NTs) as the nitrogen source. Exchange of zeolite Y with other cations (Ag+
- Langham, Christopher,Taylor, Sophia,Bethell, Donald,McMorn, Paul,Bulman Page, Philip C.,Willock, David J.,Sly, Chris,Hancock, Frederick E.,King, Frank,Hutchings, Graham J.
-
p. 1043 - 1049
(2007/10/03)
-
- Pyridinium hydrobromide perbromide: A versatile catalyst for aziridination of olefins using chloramine-T
-
Formula presented Pyridinium hydrobromide perbromide (PyHBr3) catalyzes effectively the aziridination of electron-deficient as well as electron-rich olefins using Chloramine-T (N-chloro-N-sodio-p-toluenesulfonamide) as a nitrogen source to afford the corr
- Ali, Sayyed Iliyas,Nikalje, Milind D.,Sudalai
-
p. 705 - 707
(2008/02/12)
-
- Cleavage of sulfonamides with phenyldimethylsilyllithium
-
The toluene-p-sulfonamides of secondary amines and indoles are cleaved by treatment with phenyldimethylsilyllithium to give the secondary amines. Aziridine toluene-p-sulfonamides, however, are opened by attack of the silyllithium reagent on carbon to give β-silylethyl sulfonamides. The aziridine toluene-p-sulfonamide 22 derived from norbornene is different in giving the 2-[dimethyl(phenyl)silyl]-4-methylbenzenesulfonamide 23 of exo-norbornylamine. The aziridine toluene-p-sulfonamides 26, 28 and 30, derived from methyl cinnamate, methyl acrylate and cinnamyl acetate, are also anomalous, giving 3-[N-(p-tolylsulfonyl)amino]-3-phenylpropionic acid 27, {3-[N-(p-tolylsulfonyl)amino]propionyl}-dimethyl(phenyl)silane 29 and trans-cinnamyl alcohol 31, respectively, each derived by opening of the aziridine ring followed by loss of the silyl group.
- Fleming, Ian,Frackenpohl, Jens,Ila, Hiriyakkanavar
-
p. 1229 - 1235
(2007/10/03)
-
- Development of the copper-catalyzed olefin aziridination reaction
-
Soluble Cu(I) and Cu(II) triflate and perchlorate salts are efficient catalysts for the aziridination of olefins employing (N-(p-tolylsulfonyl)imino)phenyliodinane, PhI=NTs, as the nitrene precursor. Electron-rich as well as electron-deficient olefins und
- Evans, David A.,Faul, Margaret M.,Bilodeau, Mark T.
-
p. 2742 - 2753
(2007/10/02)
-
- Copper-Catalyzed Aziridination of Olefins by (N-(p-Toluenesulfonyl)imino)phenyliodinane
-
The Cu(I)- or Cu(II)-catalyzed aziridination of both electron-rich and electron-deficient olefins employing (N-(p-toluenesulfonyl)imino)phenyliodinane, PhI=NTs, as the nitrene precursor, affords N-tosylaziridines in yields ranging between 55percent - 95pe
- Evans, David A.,Faul, Margaret M.,Bilodeau, Mark T.
-
p. 6744 - 6746
(2007/10/02)
-
- REACTION OF DIMETHYLOXOSULFONIUM METHYLIDE WITH N-ARYLSULFONYLAZIRIDINES - STEREOSPECIFIC CONVERSION OF N-ARYLSULFONYLAZIRIDINES TO N-ARYLSULFONYLAZETIDINES
-
Reaction of N-arylsulfonylaziridines with dimethyloxosulfonium methylide leads to the corresponding azetidines stereospecifically ; the cis-aziridines yielding the trans-azetidines and the trans-aziridines furnishing the cis-azetidines.This stereochemical course is interpreted in terms of an SN2-1,4-elimination mechanism.
- Nadir, Upender K.,Sharma, Raman L.,Koul, Veerinder K.
-
p. 1851 - 1858
(2007/10/02)
-
- Aziridination of Alkenes catalysed by Porphyrinirons: Selection of Catalysts for Optimal Efficiency and Stereospecificity
-
meso-Tetra-arylporphyriniron(III) derivatives catalyse the N-tosylaziridination of aryl-substituted styrenes by tosylimidoiodobenzene, PhINTs, a nitrogen analogue of iodosylbenzene.Three secondary reactions were found to limit the yield of N-tosylaziridination: (i) the formation of toluene-p-sulphonamide, TsNH2, which is presumably derived from hydrolysis of a possible iron-nitrene, Fe=NTs, intermediate, (ii) the conversion of the Fe(TPP)(Cl) (TPP = tetraphenylporphyrin) catalyst into an iron(III) complex where the NTs moiety is inserted into an iron-nitrogen bond of Fe(TPP)(Cl), (iii) an oxidative degradation of the porphyrin catalyst.These secondary reactions were avoided to a great extent by using anhydrous conditions and Fe(TDCPP)(ClO4) (TDCPP = tetrakis-2,6-dichlorophenylporphyrin) as a catalyst instead of Fe(TPP)(Cl) and Fe(TPP)(ClO4).Under these conditions, N-tosylaziridination of styrene, cis- and trans-stilbene, and 1,1-diphenylethylene was performed with yields between 40 and 90percent.Fe(TDCPP)(ClO4) was also found to be the best catalyst for N-tosylaziridination of aliphatic alkenes such as hex-1-ene, cyclo-octene, and cis- and trans-hex-2-enes.Although N-tosylaziridination of the two latter alkenes catalysed by Fe(TPP)(Cl) was not stereospecific, this reaction became stereospecific with Fe(TDCPP)(ClO4) as catalyst.These results show that by a proper choice of the porphyriniron catalyst, relatively good yields of N-tosylaziridination of alkenes by PhINTs can be obtained.As for 1,2-disubstituted aliphatic alkenes, syn addition of the NTs moiety to the double bond takes place.A possible mechanism is presented.
- Mahy, Jean-Pierre,Bedi, Gustave,Battioni, Pierrette,Mansuy, Daniel
-
p. 1517 - 1524
(2007/10/02)
-
- Iron- and Manganese-porphyrin Catalysed Aziridination of Alkenes by Tosyl- and Acyl-iminoiodobenzene
-
N-Substituted aziridines are formed by Fe- or Mn-porphyrin catalysed reactions of PhI=NR compounds (R = tosyl or COCF3) with alkenes; the stereochemical characteristics of these reactions are very different from those of the analogous epoxidation of alkenes by PhI=O.
- Mansuy, Daniel,Mahy, Jean-Pierre,Dureault, Annie,Bedi, Gustave,Battioni, Pierrette
-
p. 1161 - 1163
(2007/10/02)
-