Transanular Interactions in Difunctional Medium Rings, 5. Spectroscopic Investigations of Bicyclic Boraamines

Wiesmann, Reinhard F.; Rademacher, Paul

doi:10.1002/cber.19941270620

Cited by 10 publications

(2 citation statements)

References 24 publications

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“…The IP values of the monoximes 10؊12 and the monoIn Table 4, the 13 C-NMR δ values of the oxime carbon atoms of dimethoximes 7؊9 and methoximes 13؊15 are methoximes 13؊15 (Table 3) are 0.3Ϫ0.6 eV smaller than those of the two acetone derivatives owing to their larger summarized. Again, the six-membered ring compounds (7,13) are included for comparison. In addition, ∆δ values are skeletons.…”

Section: Photoelectron Spectramentioning

confidence: 99%

“…On the other hand, tween functional groups. We have so far investigated amino the corresponding twelve-membered ring derivatives popuketones [2Ϫ5] and aminoalkenes [2] as models for nucleophilic late no conformations that would allow for transannular additions, and boraalkenes [6] and aminoboranes [7] as mod-interactions. [1] In studying the influence of the ring size on els for electrophilic additions.…”

Section: Introductionmentioning

confidence: 99%

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Spectroscopic and Theoretical Investigations of Monocyclic Dioximes and Dimethoximes with Six-, Eight-, and Ten-Membered Rings

Strenge

Rademacher²

1999

Eur. J. Org. Chem.

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The dioximes 4–6 and the dimethoximes 7–9, which contain the functional groups in opposite positions of a six‐, eight‐, or ten‐membered ring, were synthesized. Their conformational properties and transannular interactions were investigated by spectroscopic (PE, 13C NMR) and theoretical (MMX, AM1, ab initio HF, and B3LYP) methods. While the cyclooctane derivatives 5 and 8 have conformations favourable for through‐space interactions of the π(CN) orbitals, in the other compounds no such interactions can be ascertained. Through‐space orbital interactions in the molecules with an eight‐membered ring lead to a splitting of the π(CN) MOs of 0.4 eV.

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Section: Photoelectron Spectramentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Spectroscopic and Theoretical Investigations of Monocyclic Dioximes and Dimethoximes with Six-, Eight-, and Ten-Membered Rings

Strenge

Rademacher²

1999

Eur. J. Org. Chem.

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Transanular Interactions in Difunctional Medium Rings, 6. Spectroscopic Investigations of Bicyclic Amino Ketones

Wiesmann

Rademacher

1994

Chem. Ber.

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The endo-?-(aminomethyl)bicyclo[3.3.l]nonan-3-ones 1-4 perties of 1-4 with those of the isochromophoric monofuncwith a primary, secondary, or tertiary amino group have been tional compounds 7-11 indicates that 1 and 2 form mixtures synthesized, and their tendency to form the corresponding with the tricyclic isomers 5 and 6, respectively, whereas 3 tricyclic amino carbinols has been investigated by theoretical and 4 show no interactions between the amino and the car-(MMX, AM1) and experimental (PE, 13C-NMR spectroscopy) bony1 group in the solely present bicyclic structures. methods. Comparison of the characteristic spectroscopic pro- Kovacic et al.[2%31 have investigated the intramolecular interaction in endo-7-(aminomethyl)bicyclo-[3.3.l]nonan-3-ones leading to tricyclic amino carbinols. While, mainly from IR and 'H-NMR spectroscopic measurements, for the parent compound 1 the tricyclic isomer 5 has been found to prevail, for the N-ethyl derivative only the bicyclic amino ketone has been detected. We have now studied 1 and the N-alkyl and N,N-dialkyl derivatives 2-4 by different methods. As in preceding investigations ['] we have used molecular and semiempirical quantum-chemical calculations (AM1 [' I) as well as photoelectron (PE) spectroscopy[61 and NMR spectroscopy. The ketone 7 and the amines 8-11 have been included in this study as monofunctional reference compounds.nN/xC,O interaction (transanular amide resonance) in cyclic amino ketones of medium ring size has been studied by PE spectroscopy and other methodd71. Syntheses endo-7-(Aminomethyl)bicyclo[3.3.1]nonan-3-one[2~ (1) or 6-hydroxy-5-azatricyclo[4.3.1. 13~s]undecane(2-azahomoadamantane, 5) and endoo-7-[(ethylamino)methyl]bicyclo-[3.3.l]nonan-3-0ne[~] (2) or 5-ethyl-6-hydroxy-5-azatricyclo-[4.3.1 .13,s]undecane (6) have been prepared by the methods described by Kovacic et al. Attempts to synthesize endo-7-[(methylamino)methyl]bicyclo[3.3.l]nonan-3-one have failed. The synthesis of endo-7-[(dimethylamino)methyl]bicyclo[3.3.l]nonan-3-one (3) has proven to be more difficult than expected. Reaction of endo-7-(iodomethyl)bicy-cl0[3.3.l]nonan-3-one[~l (12) with aqueous dimethylamine in the presence of ethyldiisopropylamine at ambient temperature does not afford 3, but by transanular cyclization tricyclo[4.3.1 .03,8]decan-4-one[91 (13) is formed. The same product is obtained when 1 is treated with bromomethane[lOl at reflux temperature in ethanol in the presence of O-NHEi 2 O * N M , , 5 6 9 LO 11 potassium carbonate If, however, the methylation is performed at ambient temperature in the presence of ethyldiisopropylamine, 3 is obtained in a yield of 64%. Alternatively, 1 is reduced to the alcohol 14[111 which affords endo-7-[(dimethylamino)methyl]bicyclo[3.3.l]nonan-3-ol (15) by

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ChemInform Abstract: Transannular Interactions in Difunctional Medium Rings. Part 5. Spectroscopic Investigations of Bicyclic Boraamines.

Wiesmann¹,

Rademacher²

1994

ChemInform

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Transanular Interactions in Difunctional Medium Rings, 5. Spectroscopic Investigations of Bicyclic Boraamines

Cited by 10 publications

References 24 publications

Spectroscopic and Theoretical Investigations of Monocyclic Dioximes and Dimethoximes with Six-, Eight-, and Ten-Membered Rings

Spectroscopic and Theoretical Investigations of Monocyclic Dioximes and Dimethoximes with Six-, Eight-, and Ten-Membered Rings

Transanular Interactions in Difunctional Medium Rings, 6. Spectroscopic Investigations of Bicyclic Amino Ketones

ChemInform Abstract: Transannular Interactions in Difunctional Medium Rings. Part 5. Spectroscopic Investigations of Bicyclic Boraamines.

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