Now showing 1 - 10 of 32
  • 2005Journal Article
    [["dc.bibliographiccitation.firstpage","1409"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","European Journal of Organic Chemistry"],["dc.bibliographiccitation.lastpage","1415"],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Yufit, Dmitry S."],["dc.contributor.author","Boese, R."],["dc.contributor.author","Blaser, D."],["dc.contributor.author","Schreiner, Peter R."],["dc.contributor.author","de Meijere, Armin"],["dc.date.accessioned","2018-11-07T11:15:09Z"],["dc.date.available","2018-11-07T11:15:09Z"],["dc.date.issued","2005"],["dc.description.abstract","1,3-Diisopropyl- (4), 1-tert-butyl-3-isopropyl- (5), 1,3,5-triisopropyl- (6) and 1-tert-butyl-3,5-diisopropyladamantane (7) were prepared from the same synthetic precursor - methyl 3-isopropyladamantane-1-carboxylate (10) - applying a standard set of repetitive procedures in 65, 77, 24, and 34 % overall yield, respectively. 1,3,5,7-Tetraethenyladamantane (17) was obtained in two steps - Swern oxidation and Wittig olefination - from 1,3,5,7-tetrakis(hydroxymethyl)adamantane (15) in 45 % overall yield and converted into 1,3,5,7-tetracy-clopropyladamantane (8) by fourfold cyclopropanation with diazomethane catalyzed by palladium(II) acetate (91 % yield). Hydrogenolysis of 8 over a platinum catalyst furnished 1,3,5,7-tetraisopropyladamantane (9) in quantitative yield. 1-Isopropyladamantane (3) as well as the hydrocarbons 4-7 did not give any crystals suitable for X-ray crystal structure analysis, even when using the Optical Heating and Crystallization Device (OHCD). This method was rather successful when applied to the tetravinyl derivative 17, X-ray crystal structure analysis of which revealed an approximately C-2- symmetric conformation in the solid state at 150 K However, no well-defined orientation was detected for the cyclopropyl groups in 8, and the molecules were severely disordered even at 30(1) K. In contrast to this, X-ray crystal structure analysis of the tetraisopropyl derivative 9 revealed an S-4-symmetric conformation for this hydrocarbon at 203 K. ((c) Wiley-VCH Verlag GmbH 1 Co. KGaA, 69451 Weinheim, Germany, 2005)."],["dc.identifier.doi","10.1002/ejoc.200400731"],["dc.identifier.isi","000228260600022"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54303"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1434-193X"],["dc.title","Conformational studies on oligosubstituted adamantane derivatives - Structural features of tetravinyl-, tetracyclopropyl-, and tetraisopropyladamantane"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2012Journal Article
    [["dc.bibliographiccitation.firstpage","6953"],["dc.bibliographiccitation.issue","35"],["dc.bibliographiccitation.journal","European Journal of Organic Chemistry"],["dc.bibliographiccitation.lastpage","6958"],["dc.contributor.author","de Meijere, Armin"],["dc.contributor.author","Redlich, Stefan"],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Yufit, Dmitry S."],["dc.contributor.author","Magull, Joerg"],["dc.contributor.author","Vidovic, Denis"],["dc.contributor.author","Schill, Heiko"],["dc.contributor.author","Menzel, Henning"],["dc.date.accessioned","2018-11-07T09:02:47Z"],["dc.date.available","2018-11-07T09:02:47Z"],["dc.date.issued","2012"],["dc.description.abstract","(E,E)-1,2,3,4-Tetracyclopropylbuta-1,3-diene (3) and (Z,Z)-1,4-diodo-1,2,3,4-tetracyclopropylbuta-1,3-diene (4) were prepared from dicyclopropylacetylene via an intermediate 2,3,4,5-tetracyclopropyltitanacyclopentadiene (2) in 91 and 77% yield, respectively. In the crystal, 3 adopts a conformation with an almost coplanar (phi = 163 degrees) 1,3-diene core, with the inner vinylcyclopropane units in an orthogonal and the outer vinylcyclopropane moieties in an s-trans orientation. This diene, like 2,3-cyclopropylbuta-1,3-diene (5), undergoes facile concerted [4+2] cycloadditions at 130 degrees C with dimethyl acetylenedicarboxylate as well as N-phenylmaleimide and at 0 degrees C with N-phenyltriazolinedione. An X-ray crystal structure analysis of 2,3-dicyclopropylbuta-1,3-diene (5) also reveals a coplanar inner core with the vinylcyclopropane units in essentially orthogonal (phi(av)=89.3 degrees) orientation. Differential scanning calorimetry (DSC) measurements indicate that 3 undergoes significant internal reorganization on going from the liquid to the crystalline phase, and a gauche conformer of 3 may well be favored over the s-trans conformer in the liquid."],["dc.identifier.doi","10.1002/ejoc.201201054"],["dc.identifier.isi","000312035900015"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24762"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1434-193X"],["dc.title","(E,E)-1,2,3,4-Tetracyclopropylbuta-1,3-diene: Synthesis and Some of Its Properties"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2002Journal Article
    [["dc.bibliographiccitation.firstpage","2499"],["dc.bibliographiccitation.issue","15"],["dc.bibliographiccitation.journal","European Journal of Organic Chemistry"],["dc.bibliographiccitation.lastpage","2507"],["dc.contributor.author","Gensini, M."],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Yufit, Dmitry S."],["dc.contributor.author","Howard, JAK"],["dc.contributor.author","Es-Sayed, M."],["dc.contributor.author","de Meijere, Armin"],["dc.date.accessioned","2018-11-07T10:14:23Z"],["dc.date.available","2018-11-07T10:14:23Z"],["dc.date.issued","2002"],["dc.description.abstract","A variety of tris- and monoprotected derivatives with the 1-amino-3-azabicyclo[4.1.0]hexane and 1-amino-3-azabicyclo[4.1.0]heptane skeleton 10 have been synthesized by intramolecular reductive cyclopropanation of alpha-(N-allylamino)substituted N,N-dialkylcarboxamides 6, 8, and 9. Starting from derivatives of the naturally occurring amino acid serine (4a, 4b), the enantiomerically pure compounds 10a and 10b were obtained with endo/exo ratios of 2.5:1 (a) and 2:1 (b), in 26 and 30% overall yields, respectively. The unprotected bicyclic amines 11aa, 11ab, 11ba, and 11ad have been prepared by palladium-catalyzed hydrogenative deprotection of 10aa, 10ab, 10ba and 10ad, respectively, under acidic conditions, in 91, 95, 96, and 99% yields, respectively. X-ray crystal structure analyses of 10aa and 10ad in each case found an equatorial position of the N-benzyl group on the heterocycle and a common boat conformation for the 3-azabicyclo[3.1.0]hexane and 3-azabicyclo[4.1.0]heptane skeletons as a whole. One-step preparations of the bicyclic diamines I lac (41% yield) and 14a (48% yield) have been performed by application of the Kulinkovich-de Meijere procedure to the nitriles 12a and 12b."],["dc.identifier.isi","000177298100008"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40607"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1434-193X"],["dc.title","3-azabicyclo[3.1.0]hex-1-ylamines by Ti-mediated intramolecular reductive cyclopropanation of alpha-(N-allylamino)-substituted N,N-dialkylcarboxamides and carbonitriles"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2004Journal Article
    [["dc.bibliographiccitation.firstpage","289"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","European Journal of Organic Chemistry"],["dc.bibliographiccitation.lastpage","303"],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Langer, R."],["dc.contributor.author","Yufit, Dmitry S."],["dc.contributor.author","Howard, JAK"],["dc.contributor.author","Schill, H."],["dc.contributor.author","Demus, D."],["dc.contributor.author","Miyazawa, K."],["dc.contributor.author","de Meijere, Armin"],["dc.date.accessioned","2018-11-07T10:51:46Z"],["dc.date.available","2018-11-07T10:51:46Z"],["dc.date.issued","2004"],["dc.description.abstract","Additions of ethyl or tert-butyl diazoacetates to 4-substituted cyclopentenes 6 and 17 under dirhodium tetraacetate/tetraoctanoate catalysis led to mixtures of tert-butyl endo,exo and exo,exo-3-carboxyl(aryl)bicyclo[3.1.0]hexane-6-carboxylates 7 and 18 in yields of 54-90% from which exo,exodiastereomers were isolated in yields of 39-63%. Diester exo,exo-7 was saponified and converted into diaryl diesters exo,exo-9a,b in overall yields of 42 and 46%, respectively. The esters exo,exo-18 were reduced to the corresponding hydroxymethyl derivatives, these were transformed to the iodomethyl compounds which in turn were coupled with various alkylmagnesium halides, via Li2CuCl4 catalysis, to give 3-aryl-6-alkylbicyclo[3.1.0]hexyl derivatives exo,exo-21 in overall yields of 72-83%. Fluorinated 3-(2-arylethyl)-6-pentylbicyclo[3.1.0]hexane exo,exo-32 could be prepared in five steps from 4-ethoxy-2,3-difluorobenzaldehyde 26a adopting essentially the same synthetic strategy, but in an overall yield of only 8%, and 6-(4-cyanophenyl)-3-pentylbicyclo[3.1.0]hexane exo,exo-38b was obtained by Pd(OAC)(2) catalyzed cyclopropanation of 4-pentylcyclopentene 34b with (4-cyanophenyl)diazomethane 36b in 29% yield. A comparison of the liquid crystalline properties of these newly prepared compounds containing a bicyclo[3.1.0]hexane core with those of the known analogous compounds with a cyclohexane fragment shows that as a rule, a bicyclo[3.1.0]hexane moiety decreases the transition temperature, while the dielectric (Deltaepsilon) and optical (Deltan) anisotropies are comparable. However, the bicyclo[3.1.0]hexane unit has a poorer mesogenic potential."],["dc.identifier.doi","10.1002/ejoc.200300448"],["dc.identifier.isi","000188531600006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/48960"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1434-193X"],["dc.title","Novel liquid crystalline compounds containing bicyclo[3.1.0]hexane core units"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2001Journal Article
    [["dc.bibliographiccitation.firstpage","968"],["dc.bibliographiccitation.journal","ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS"],["dc.bibliographiccitation.lastpage","969"],["dc.bibliographiccitation.volume","57"],["dc.contributor.author","Yufit, Dmitry S."],["dc.contributor.author","Howard, JAK"],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Kostikov, Rafael R."],["dc.contributor.author","de Meijere, Armin"],["dc.date.accessioned","2018-11-07T08:46:14Z"],["dc.date.available","2018-11-07T08:46:14Z"],["dc.date.issued","2001"],["dc.description.abstract","The central three-membered ring in the title compound, trans-1,1',1\"-cyclopropane-1,2,3-triyltris(cyclopropanol), C12H18O3, shows pronounced asymmetry of the bond lengths, which is induced by the different orientations of the substituents. A network of hydrogen bonds links the molecules into sheets."],["dc.identifier.doi","10.1107/S010827010100796X"],["dc.identifier.isi","000170319500032"],["dc.identifier.pmid","11498629"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/20639"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Munksgaard Int Publ Ltd"],["dc.relation.issn","0108-2701"],["dc.title","trans-1,2,3-Tris(1-hydroxycyclo-propyl)cyclopropane"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2003Journal Article
    [["dc.bibliographiccitation.firstpage","869"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","European Journal of Organic Chemistry"],["dc.bibliographiccitation.lastpage","877"],["dc.contributor.author","Larionov, Oleg V."],["dc.contributor.author","Savel'eva, T. F."],["dc.contributor.author","Kochetkov, K. A."],["dc.contributor.author","Ikonnokov, N. S."],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Yufit, Dmitry S."],["dc.contributor.author","Howard, JAK"],["dc.contributor.author","Khrustalev, V. N."],["dc.contributor.author","Belokon, Y. N."],["dc.contributor.author","de Meijere, Armin"],["dc.date.accessioned","2018-11-07T10:40:20Z"],["dc.date.available","2018-11-07T10:40:20Z"],["dc.date.issued","2003"],["dc.description.abstract","All four diastereomers of 3 - (trans-2-nitrocyclopropyl) alanine (3) were prepared by asymmetrically induced a-C alkylation of the glycine moiety in the [(S)- or (R)-Schiff base]Ni-II complex 7, employing racemic trans-1-(iodomethyl)-2-nitrocyclopropane (8) as the alkylating agent. A notable difference in solubility between the two diastereomeric products 9a/9b [when (S)-7 was used as starting material] or 9d/9e [when (R)-7 was employed] allowed for their separation from the same reaction mixture. All the diastereomers of 3-(trans-2nitrocyclopropyl)alanine (3) were produced upon brief exposure of the alkylation products 9 to dilute hydrochloric acid, with subsequent purification by ion-exchange chromatography and crystallization. The absolute configurations of the nickel complexes 9a-e were established by X-ray crystallographic analyses. In addition, the X-ray crystal structure of (2S,1'S,2'R)-3 was determined to confirm the convergence of the configurations of the parent nickel complexes 9 with those of the amino acids 3 derived from them. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003."],["dc.identifier.isi","000181301200010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/46282"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1434-193X"],["dc.title","Productive asymmetric synthesis of all four diastereomers of 3-(trans-2-nitrocyclopropyl)alanine from glycine with (S)- or (R)-2-[(N-benzylprolyl)amino]benzophenone as a reusable chiral auxiliary"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2007Journal Article
    [["dc.bibliographiccitation.firstpage","167"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Chemistry - A European Journal"],["dc.bibliographiccitation.lastpage","177"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Seebach, Malte von"],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Schill, Heiko"],["dc.contributor.author","Frank, Daniel"],["dc.contributor.author","Boese, Roland"],["dc.contributor.author","Benet-Buchholz, Jordi"],["dc.contributor.author","Yufit, Dmitry S."],["dc.contributor.author","Meijere, Armin de"],["dc.date.accessioned","2018-11-07T11:06:12Z"],["dc.date.available","2018-11-07T11:06:12Z"],["dc.date.issued","2007"],["dc.description.abstract","Diastereomeric meso- and d,l-bis(bicyclopropylidenyl) (5) were obtained upon oxidation with oxygen of a higher-order cuprate generated from lithiobicyclopropylidene (4) in 50 and 31 % yield, respectively. Their perdeuterated analogues meso-[D(14)]- and d,l-[D(14)]-5 were obtained along the same route from perdeuterated bicyclopropylidene [D(8)]-3 (synthesized in six steps in 7.4% overall yield from [D(8)]-THF) in 20.5 % yield each. Dehalogenative coupling of 1,1-dibromo-2-cyclopropylcyclopropane (6) gave a mixture of all possible stereoisomers of 1,5-dicyclopropylbicyclopropylidene 16 in 69% yield, from which (Z)-cis-16 was separated by preparative gas chromatography (26% yield). The crystal structure of meso-5 looks like a superposition of the crystal structures of two outer bicyclopropylidene units (3) and one inner s-trans-bicyclopropyl unit, whereas the two outer cyclopropyl moieties adopt a gauche orientation with respect to the cyclopropane rings at the inner bicyclopropylidene units in (Z)-cis-16. Birch reduction with lithium in liquid ammonia of meso-5 and d,l-5 gave two pairs of diastereomeric quatercyclopropanes trans,trans-(R ,S ,R , S )-17/cis,trans-(R ,S ,R ,R )-18 and trans,trans-(R ,S ,S ,R )-19/cis,trans- (R ,S ,S ,S )-20 in 97 and 76% yield, respectively, in a ratio 9:1 for every pair. The latter diastereomer was also obtained as the sole product by Birch reduction of (Z)-cis-16 in 96% yield. Under the same conditions, tetradecadeuterio analogues trans,trans-[D(14)](R ,S ,R ,S )-171cis,trans-[D(14)]-(R , S ,R ,R )-18 (8:1) and trans,trans[D(14)]-(R ,S ,S ,R )-19/cis,trans-[D(14)]- (R ,S ,S ,S )-20 (12:1) were prepared from meso-[D(14)]-5 and d,l-[D(14)]-5 in 37 and 63% yield, respectively. Reduction of meso-5 with diimine gave the cis,cisquatercyclopropane (S ,S ,R ,R )-21 as the main product (58% yield) along (Z)-cis-16. Birch reduction with lithium in liquid ammonia of meso-5 and d,l-5 gave two pairs of diastereomeric quatercyclopropanes trans,trans-(R ,S ,R , S )-17/cis,trans-(R ,S ,R ,R )-18 and trans,trans-(R ,S ,S ,R )-19/cis,trans-(R ,S ,S ,S )-20 in 97 and 76% yield, respectively, in a ratio 9:1 for every pair. The latter diastereomer was also obtained as the sole product by Birch reduction of (Z)-cis-16 in 96% yield. Under the same conditions, tetradecadeuterio analogues trans,trans-[D(14)](R ,S ,R ,S )-17/cis,trans-[D(14)]-(R , S ,R ,R )-18 (8:1) and trans,trans[D(14)]-(R ,S ,S ,R )-191cis,trans-[D(14)]- (R ,S ,S ,S )-20 (12:1) were prepared from meso-[D(14)]-5 and d,l-[D(14)]-5 in 37 and 63% yield, respectively. Reduction of meso-5 with diimine gave the cis,cis-quatercyclopropane (S ,S ,R ,R )-21 as the main product (58% yield) along with the cis,trans-diastereomer (S ,S ,R ,S )-18 (29 % yield). Thus, five of the six possible diastereomeric quatercyclopropanes were obtained from meso-5, d,l-5, and (Z)-cis-16. ne X-ray crystal structure analyses of trans, trans- (R ,S ,R ,S ) - 17 and cis,cis(S ,S ,R ,R )-21 revealed for the both an unusual conformation in which the central bicyclopropyl unit adopts an strans- (anti periplanar) orientation with phi=180.0 degrees, and the two terminal bicyclopropyl moieties adopt a synclinal conformation with phi=49.8 and 72.0 degrees, respectively. In solution the vicinal coupling constants <(3)J(H,H)> in trans,trans(R ,S ,R ,S )-[D(14)]-17, trans,trans(R ,S ,S ,R )-[D(14)]-19, trns,cis(R ,S ,R ,R )-[D(14)]-18 and trans,cis(R ,S ,S ,S )-[D(14)]-20 were found to be 4.1, 4.7, 5.9 and 5.9 Hz, respectively. This indicates a predominance of the all-gauche conformer in (R ,S ,R ,S )17 and a decreasing fraction of it in this sequence of the other diastereomers."],["dc.identifier.doi","10.1002/chem.200600799"],["dc.identifier.isi","000244231500015"],["dc.identifier.pmid","17024706"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52252"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0947-6539"],["dc.title","Stereoselective preparation of six diastereomeric quatercyclopropanes from bicyclopropylidene and some derivatives"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]
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  • 2003Journal Article
    [["dc.bibliographiccitation.firstpage","15110"],["dc.bibliographiccitation.issue","49"],["dc.bibliographiccitation.journal","Journal of the American Chemical Society"],["dc.bibliographiccitation.lastpage","15113"],["dc.bibliographiccitation.volume","125"],["dc.contributor.author","de Meijere, Armin"],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Rauch, K."],["dc.contributor.author","Schill, H."],["dc.contributor.author","Verevkin, S. P."],["dc.contributor.author","Kummerlin, M."],["dc.contributor.author","Beckhaus, H. D."],["dc.contributor.author","Ruchardt, C."],["dc.contributor.author","Yufit, Dmitry S."],["dc.date.accessioned","2018-11-07T10:34:07Z"],["dc.date.available","2018-11-07T10:34:07Z"],["dc.date.issued","2003"],["dc.description.abstract","The enthalpies of formation [DeltaH(t)(o)(g)] of tricyclo[8.2.2.2(4.7)]hexadeca-1(13),2,4(16),5,7(15),10-(14),11-heptaene (2, 1,2-dehydro[2.2]paracyclophane or [2.2]paracyclophane-1-ene) and tricyclo[8.2.2.2(4.7)]-hexadeca-1(13),2,4(16),5,7(15),8,10(14),11-octaene (3, 1,2,9,10-dehydro[2.2]paracyclophane or [2.2]-paracyclophane-1,9-diene) have been determined by measuring their heats of combustion in a microcalorimeter and their heats of sublimation by the transpiration method. Values of the strain energies (SE) [SE(2) = 34.7 kcal mol(-1), SE(3) = 42.0 kcal mol-1] have been derived from the gas-phase heats of formation and are compared with those from MM3 and PM3 calculations and with the corresponding value SE(1) = 30.1 kcal mol(-1) for the parent tricyclo[8.2.2.2(4.7)]hexadeca-1(13),4(16),5,7(15),10(14),11-hexaene (1, [2.2]-paracyclophane). The higher strain energies of 2 and 3 (by 4.6 and 11.9 kcal mol(-1)) are in accord with the well-known increased reactivities of their aromatic rings as a consequence of their increased bending. As revealed by an X-ray crystal structure analysis, the bending in the monoene 2 corresponds to that of 1 and 3 at one of two bridging corners."],["dc.identifier.doi","10.1021/ja0374628"],["dc.identifier.isi","000187007400040"],["dc.identifier.pmid","14653746"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/44780"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","0002-7863"],["dc.title","Heats of formation of [2.2]paracyclophane-1-ene and [2.2]paracyclophane-1,9-diene - An experimental study"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2010Journal Article
    [["dc.bibliographiccitation.firstpage","3481"],["dc.bibliographiccitation.issue","18"],["dc.bibliographiccitation.journal","European Journal of Organic Chemistry"],["dc.bibliographiccitation.lastpage","3486"],["dc.contributor.author","Rassadin, Valentin A."],["dc.contributor.author","Grosheva, Daria S."],["dc.contributor.author","Tomashevskiy, Alexander A."],["dc.contributor.author","Sokolov, Viktor V."],["dc.contributor.author","Yufit, Dmitry S."],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","de Meijere, Armin"],["dc.date.accessioned","2018-11-07T08:42:34Z"],["dc.date.available","2018-11-07T08:42:34Z"],["dc.date.issued","2010"],["dc.description.abstract","A practical synthesis of bicyclic sultams with a pyramidal bridgehead nitrogen atom and a sulfur atom in the apex position has been elaborated. Compounds with 1-azathiabicyclo[2.2.1]heptane (12a), -bicyclo[3.2.1]octane (12b, 12d), and -bicyclo[3.3.1]nonane (13b) skeletons were obtained by direct twofold inter/intramolecular alkylation of corresponding monocyclic sultams 9 and 10 with alpha,omega-dihalides 11 in K(2)CO(3)/DMF in 56, 68, 52 and 52% yield, respectively. On the other hand, a 1-aza-9-thiabicyclo[4.2.1]nonane derivative (12c) could be prepared only by stepwise dialkylation in 24% overall yield. Structural and conformational properties of four of the newly prepared bicyclic sultams in solution as well as in the solid state are discussed."],["dc.description.sponsorship","Land Niedersachsen; KAd-eMCustomChem GmbH, Gottingen"],["dc.identifier.doi","10.1002/ejoc.201000345"],["dc.identifier.isi","000279746300015"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19732"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1434-193X"],["dc.title","Bicyclic Sultams with a Nitrogen at the Bridgehead and a Sulfur Atom in the Apex Position: Facile Preparation and Conformational Properties"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2011Journal Article
    [["dc.bibliographiccitation.firstpage","1003"],["dc.bibliographiccitation.journal","Beilstein Journal of Organic Chemistry"],["dc.bibliographiccitation.lastpage","1006"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Khlebnikov, Alexander F."],["dc.contributor.author","Kostikov, Rafael R."],["dc.contributor.author","Yufit, Dmitry S."],["dc.contributor.author","de Meijere, Armin"],["dc.date.accessioned","2018-11-07T08:54:14Z"],["dc.date.available","2018-11-07T08:54:14Z"],["dc.date.issued","2011"],["dc.description.abstract","1-Cyclopropylcyclopropanecarboxylic acid (2), which is accessible on a large scale (900 mmol) from 1-bromo-1-cyclopropylcyclopropane (1) in 64% yield (89% on a 12.4 mmol scale), has been subjected to a Curtius degradation employing the Weinstock protocol to furnish the N-Boc-protected (1-cyclopropyl) cyclopropylamine 3 (76%). Deprotection of 3 with hydrogen chloride in diethyl ether gave the (1-cyclopropyl) cyclopropylamine hydrochloride (4 center dot HCl) in 87% yield."],["dc.description.sponsorship","Land Niedersachsen"],["dc.identifier.doi","10.3762/bjoc.7.113"],["dc.identifier.isi","000292998300001"],["dc.identifier.pmid","21915200"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22625"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Beilstein-institut"],["dc.relation.issn","1860-5397"],["dc.title","Scalable synthesis of (1-cyclopropyl)cyclopropylamine hydrochloride"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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