Über aliphatische Nitroverbindungen, XXI: Die Darstellung von α‐Chlor‐oximen aus Nitroolefinen

Dornow, Alfred; Jordan, Heinz Dietrich; Müller, Arno

doi:10.1002/cber.19610940111

Cited by 29 publications

(6 citation statements)

References 19 publications

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“…Bibenzyl is indicative of triplet dibenzyl ketone, which yields bibenzyl by a type I process. 3 Benzyl chloride is detected in the reaction mixture when 1 is decomposed at 60°in degassed carbon tetrachloride, which indicates that bibenzyl is produced from free benzyl radicals as proposed in the type 1 process. 3 Further evidence for excited state carbonyl species from the thermal decomposition of 1 is shown by the production of chemiluminescence when 9,10-diphenylanthracene is incorporated in the reaction mixture.…”

Section: Phcch2brmentioning

confidence: 86%

“…3 Benzyl chloride is detected in the reaction mixture when 1 is decomposed at 60°in degassed carbon tetrachloride, which indicates that bibenzyl is produced from free benzyl radicals as proposed in the type 1 process. 3 Further evidence for excited state carbonyl species from the thermal decomposition of 1 is shown by the production of chemiluminescence when 9,10-diphenylanthracene is incorporated in the reaction mixture. To show that chemiluminescence with 9,10-diphenylanthracene is intimately related to the excited state carbonyl species generated from 1, quenching of bibenzyl formation with 9,10-diphenylanthracene was measured.…”

Section: Phcch2brmentioning

confidence: 86%

“…When II (1.9 X 10-4 M) is solvolyzed in the absence of Brin pH 4, 0.01 M acetate buffer, for example, there is a first-order decrease in the absorbance at 260 nm ( /2 = 6 sec), corresponding to replacement of the bromide in the substrate by acetate. However, in the presence of 0.5 M Br-, there is an increase in absorbance to a maximum value, reached after 3 extraction, the product responsible for the initial rise in absorbance was identified as sjn-a-bromoacetophenone oxime (I).…”

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confidence: 99%

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Kinetics and stereochemistry of nucleophilic reactions of phenacyl halide oximes

Smith¹,

Heidema²,

Kaiser³

1972

J. Am. Chem. Soc.

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Br-C(l)-C(2) 109.0 0.5 C(l)-C(2) 1.509 0.010 C(l)-C(2)-C(3) 120.3 0.7 C(2)-C(3) 1.474 0.011 C(l)-C(2)-N 112.5 0.7 C(2)-N 1.291 0.010 N-C(2)-C(3) 127.2 0.6 N-O 1.409 0.008 C(2)-N-D 113.5 0.7 C(3)-C(4) 1.404 0.010 C(2)-C(3)-C(4) 119.3 0.7 C(4)-C(5) 1.366 0.015 C(2)-C(3)-C(8) 122.1 0.6 C(5)-C(6) 1.358 0.015 C(4)-C(3)-C(8) 118.6 0.7 C(6)-C(7) 1.389 0.015 C(3)-C(4)-C(5) 120.5 0.8 C(7)-C(8) 1.385 0.014 C(4)-C(5)-C(6) 121.0 0.9 C(8)-C(3) 1.402 0.011 0.2919(9) 0.9511 (8) 0.3123 (8) C(ll) 0.3358(7) 0.9864 (7) 0.4120(8)from the National Science Foundation (J.

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Section: Phcch2brmentioning

confidence: 86%

Section: Phcch2brmentioning

confidence: 86%

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confidence: 99%

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Kinetics and stereochemistry of nucleophilic reactions of phenacyl halide oximes

Smith¹,

Heidema²,

Kaiser³

1972

J. Am. Chem. Soc.

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“…The second method includes interaction of nitro alkenes with SnCl 2 23 or TiCl 4 . 8 It is used to prepare some a-chloro oximes or achlorohydroxyiminoyl chlorides, respectively.…”

Section: Methods For Generation Of Nitrosoalkenes 1 14-elimination In...mentioning

confidence: 99%

Conjugated nitrosoalkenes

Lyapkalo¹,

Ioffe²

1998

Russ. Chem. Rev.

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Published data on the preparation, structure, physical and chemical properties, and reactivity of nitrosoalkenes are described systematically. The influence of the structure and stereoelectronic effects of substituents at the double bond on the stability of nitrosoalkenes is analysed. Primary attention is paid to concerted cycloaddition of nitrosoalkenes to miscellaneous multiple bonds, in particular, to the problems of regio-, stereo-, and enantioselectivity of [4 + 2]-cycloaddition of nitrosoalkenes to alkenes. The bibliography includes 183 references.

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“…Labelling studies (Table 5) show that the formation of H Ospecifically involves the methine hydrogen, and that the loss of this hydrogen together with statistical loss of a ring hydrogen constitutes the H 2 0 loss. These processes are summarised in equations (26) and ( 27) (Scheme 4), and it is process (26) which gives rise to the dish-shaped peak shown in Figure 5…”

Section: Cn-ho-1mentioning

confidence: 99%

Gas-phase rearrangements of deprotonated ketoximes, ketoxime ethers, and aldoximes. A negative-ion beckmann rearrangement

Adams¹,

Bowie²,

Hayes³

1989

J. Chem. Soc., Perkin Trans. 2

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Evidence is presented which indicates that the pronounced loss of water from deprotonated ketoximes involves specific proton transfer followed by a negative-ion Beckmann rearrangement.For example, Me,C=NO---+ -CH,(Me)C=NOH 0 [(CH,=C=NMe)-OH] --+ CHpC=NCH2-+ H20. Deprotonated aldoximes, e.g. MeCH=NO-, fragment in this way, but also undergo the competing process MeCH=NO---+ MeC=NOH --[(MeCN) -OH] --+ -CH,CN + H20. Other rearrangements occur when proton transfer to oxygen does not occur; e.g. PhO-+ PhCN.We have recently reported a number of simple 'rules' for fragmentations of even-electron negative ions including enolates, C-, N -, and 0species.'T2 Most fragmentations involve loss of a neutral molecule, and many such reactions are initiated from the charged centre through ion complexes [e.g. equation (l), R' = H, alkyl or aryl]. When such reactions are either unfavourable or not possible, one of two events generally occurs, viz. ( i ) proton transfer to the original charged centre produces a new anion which may fragment [e.g. carboxylate species, equations ( 2 ) and (3)3Jt or (ii) some type of internal (skeletal) rearrangement occurs (e.g. sigmatropic 5 * 6 and Smiles [equation (4)] rearrangements). Deprotonated oximes (R')(R2CH2)C=NO-(R' and R2 = H, alkyl or aryl), are somewhat akin to carboxylate species [see equations ( 2) and (3)], since it is unlikely that fragmentation can be directly effected through 0-. Either proton transfer to oxygen, or some internal rearrangement would be expected to precede fragmentation. Proton transfer [see equation (5)] could be facile since the acidities at the two centres should differ only by some 30 kJ mol-'. For example, the gas phase AH&i, values for Me2C=NOHs and (CH3),C=NOMe9 are 1 532 and 1 561 kJ mol-' respectively.This paper reports the basic fragmentations of deprotonated ketoximes, ketoxime ethers and aldoximes, and provides evidence in favour of a number of rearrangement reactions including the negative-ion Beckmann rearrangement. Results and DiscussionCollision-induced Dissociations of Deprotonated Alkyl Ketoximes.-Alkyl ketoxime spectra are listed in Table 1 or recorded in Figures 1-3. Deprotonation was effected by NH,: under these conditions, R2C=NOD systems yield M -D+ and M -H + ions in the approximate ratio 4-5: 1. This is the expected result since although the O H position is the more acidic, O H and -CHC=N-differ in acidity by only some 30 kJ mol-'. Labelling experiments are crucial for this study, and exchange reactions must be carried out with care because of the similarities in acidity at the two described positions. Full details are provided in the Experimental section.The oxime of acetone is prototypical in this series; its decompositions are shown in Figures 1 and 2. Major fragmentations shown in Figure 1 are the loss of H', the losses of H 2 0 and CH, and the formation of HO-. Less abundant * Numbers listed in the table refer to relative abundances of peaks with reference to base peak (100%) of that spectrum.a Loss of MeOH yields -CH,CN. approximate rat...

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Über aliphatische Nitroverbindungen, XXI: Die Darstellung von α‐Chlor‐oximen aus Nitroolefinen

Abstract: Nitroolefine ergeben bei der Reduktion mit Zinn(II)‐chlorid in Äther in Gegenwart von Chlorwasserstoff α‐Chlor‐oxime. Der Reaktionsmechanismus wird erörtert und eine zusammenfassende Deutung aller bekannten Umsetzungen von Nitroolefinen mit Zinn(II)‐chlorid gegeben.

Cited by 29 publications

References 19 publications

Kinetics and stereochemistry of nucleophilic reactions of phenacyl halide oximes

Kinetics and stereochemistry of nucleophilic reactions of phenacyl halide oximes

Conjugated nitrosoalkenes

Gas-phase rearrangements of deprotonated ketoximes, ketoxime ethers, and aldoximes. A negative-ion beckmann rearrangement

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