Untersuchungen an Diazoverbindungen und Aziden, XXX: <i>C</i>‐Alkylierung von Diazomethylphosphorylverbindungen mit Enaminen

Welter, W.; Regitz, Manfred; Heydt, H.

doi:10.1002/cber.19781110624

Cited by 9 publications

(1 citation statement)

References 23 publications

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“…In the ' s Regitz's g oup pu lished so e pape s epo ti g the su stitutio of the α-hydrogen of dimethyl α-diazomethylphosphonate (5a) and diphenyl α-diazomethylphosphinoxide (2b) by electrophilic reagents. 66,67,68,33 Fu the o e, α-e z l-α-diazo eth lphospho ate de i ati es e e e e tl p epa ed i e good ield the ea tio of e z l o ides ith the a io of a, ge e ated i -situ f o BOR " he e . Ho e e , i the ase of e z l o ides ea i g ele t o -ithd a i g su stitue ts at the orthoo parapositio , it oge eli i atio o u ed fu ishi g the espe ti e st lphospho ates .…”

Section: C-c Coupli G Of Te I Al Pcdc Ith Ele T Ophilesmentioning

confidence: 99%

λ⁵-Phosphorus-Containing α-Diazo Compounds: A Valuable Tool for Accessing Phosphorus-Functionalized Molecules

2016

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The compounds characterized by the presence of a λ-phosphorus functionality at the α-position with respect to the diazo moiety, here referred to as λ-phosphorus-containing α-diazo compounds (PCDCs), represent a vast class of extremely versatile reagents in organic chemistry and are particularly useful in the preparation of phosphonate- and phosphinoxide-functionalized molecules. Indeed, thanks to the high reactivity of the diazo moiety, PCDCs can be induced to undergo a wide variety of chemical transformations. Among them are carbon-hydrogen, as well as heteroatom-hydrogen insertion reactions, cyclopropanation, ylide formation, Wolff rearrangement, and cycloaddition reactions. PCDCs can be easily prepared from readily accessible precursors by a variety of different methods, such as diazotization, Bamford-Stevens-type elimination, and diazo transfer reactions. This evidence along with their relative stability and manageability make them appealing tools in organic synthesis. This Review aims to demonstrate the ongoing utility of PCDCs in the modern preparation of different classes of phosphorus-containing compounds, phosphonates, in particular. Furthermore, to address the lack of precedent collective papers, this Review also summarizes the methods for PCDCs preparation.

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Section: C-c Coupli G Of Te I Al Pcdc Ith Ele T Ophilesmentioning

confidence: 99%

λ⁵-Phosphorus-Containing α-Diazo Compounds: A Valuable Tool for Accessing Phosphorus-Functionalized Molecules

2016

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Photochemical Rearrangements and Fragmentations of Alkenes and Polyenes

Kaupp

1978

Angew. Chem. Int. Ed. Engl.

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This article presents a systematic analysis of the numerous intramolecular reactions of electronically excited alkenes categorized according to substance class and reaction type. The rearrangements and fragmentations observed in simple alkenes are usually rediscovered in non‐conjugated and conjugated dienes and polyenes, where they are accompanied by reaction types such as rearrangements involving several double bonds, cyclizations, and intramolecular cycloadditions. Geometrical factors largely determine which reaction of a series of energetically feasible competing processes actually takes place. The industrial syntheses of vitamin D utilize many of the reaction types to be discussed.

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Untersuchungen an Diazoverbindungen und Aziden, XXI. Synthese und Isomerisierung von 2,3‐Diazabicyclo[3.1.0]hex‐2‐enen–eine neue Variante der Diazogruppen‐Übertragung

1979

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Investigations on Diazo Compounds and Azides, XXXI"Synthesis and lsomerization of 2,3-Diazabicyclo[3.1.O~hex-2-enes -a New Variant of Diazo Transfer Reaction 2-Diazopropane (5a) and diazodiphenylmethane (5b) add regiospecifically to the cyclopropenes 6a -e to yield the homopyrazoles 7a -i. Diazomethane reacts with the same dipolarophiles to form the cycloadducts 9a -e, which may he transformed either by base catalysis (9a -d) or by chromatography on silicagel (9a and e) into isomeric 1,4-dihydropyridazines (10a -e). The diastereomeric heterocycles 14a-c and 15a -c arise from dimethyl 1 -diazoethylphosphonate (13) and 6a -c by usual dipole orientation. The reaction of 6a and e with dimethyl diazobenzylphosphonate (16) leads to one isomer 17a or b , respectively. Cycloadditions of 6a and b with dimethyl diazomethanephosphonate (18a) and ethyl diazoacetate (18b) are exceptional as the [3 +2] cycloadducts 19a -d could not be isolated: they apparently isomerize spontaneously to the diazoalkanes 2Oa-d and the 1,4-dihydropyridazines 2 l a -d. -Elucidation of the constitution of the cycloadducts is based above all on thermal isomerization reactions to allyl-phosphoryl-diazomethanes (7e-b, 9a-d, 14a,b, 15b, and 17a-22a-I) which must he interpreted as intramolecular [3+2] cycloreversions. -The reactivity of methyl and phenyl azide towards 6a and b is comparable to that of diazoalkanes: they undergo [3 + 21 cycloaddition to the hitherto not isolated homotriazoles 24a -d, which isomerize to the P-iminodiazoalkanes 25a -d; 25c hydrolyzes to the p-oxodiazoalkane 26 during chromatographic purification on silicagel. Als Edukte boten sich die Phosphorylcyclopropene 2 an, die ihrerseits durch Photolyse dcr Phosphoryl-vinyl-diazomethane 1 gut zugiinglich sind 'I. Bei nachfolgender Addition von Diazoalkanen erwartet man die Bildung der Homopyrazolenine 3, die sich thermisch oder photochemisch zu den gesuchten Allyl-phosphoryl-diazomethanen 4 isomerisieren lassen sollten. Eine derartige Reaktionsfolge wurde bei der Umsetzung von 3.3-Dimethyl-lcyclopropen-1,2-dicarbonsaure-dimethylester mit Diazomethan verwirklicht, wobei der abschlieBende Jsomerisierungsschritt photochemisch erfolgte"'. Geht man dagegen von Cyclopropenonen aus, so reagieren diese mit Diazoalkanen spontan gemiiD 2 + 3 -4, ohne dafl die Heterobicyclen zu isolieren sind'.'''. Cycloadditionen mit 2-Diazopropan und Diazodiphenylmethan Cycloadditionen mit DiazomethanDiazomethan addicrt sich ebenso wie 5a und b regiospezifisch und bei gleicher Dipolorientierung quantitativ an die Cyclopropenphosphonester 6a -d zu den oligen Homopyrazoleninen 9a -d. Auch wenn diese nicht analysenrein erhalten werden konntenbei destillatiben Reinigungsversuchen tritt Zersetzung, bei der Saulenchromatographie, wie fur 9a und e gezeigt wird, 3,4-Dihydropyridazin-Isomerisierung ein -darf die angegebene Konstitution als abgesichert gelten. Die spater abgehandelten Umwandlungen 9 -10 und 9 + 22 stiitzen diese Aussage ebenso wie vor allem die 'H-NMR-spektroskopischen Daten.Etwas komplexer ver...

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Untersuchungen an Diazoverbindungen und Aziden, XXX: C‐Alkylierung von Diazomethylphosphorylverbindungen mit Enaminen

Cited by 9 publications

References 23 publications

λ⁵-Phosphorus-Containing α-Diazo Compounds: A Valuable Tool for Accessing Phosphorus-Functionalized Molecules

λ⁵-Phosphorus-Containing α-Diazo Compounds: A Valuable Tool for Accessing Phosphorus-Functionalized Molecules

Photochemical Rearrangements and Fragmentations of Alkenes and Polyenes

Untersuchungen an Diazoverbindungen und Aziden, XXI. Synthese und Isomerisierung von 2,3‐Diazabicyclo[3.1.0]hex‐2‐enen–eine neue Variante der Diazogruppen‐Übertragung

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Untersuchungen an Diazoverbindungen und Aziden, XXX: C‐Alkylierung von Diazomethylphosphorylverbindungen mit Enaminen

Cited by 9 publications

References 23 publications

λ5-Phosphorus-Containing α-Diazo Compounds: A Valuable Tool for Accessing Phosphorus-Functionalized Molecules

λ5-Phosphorus-Containing α-Diazo Compounds: A Valuable Tool for Accessing Phosphorus-Functionalized Molecules

Photochemical Rearrangements and Fragmentations of Alkenes and Polyenes

Untersuchungen an Diazoverbindungen und Aziden, XXI. Synthese und Isomerisierung von 2,3‐Diazabicyclo[3.1.0]hex‐2‐enen–eine neue Variante der Diazogruppen‐Übertragung

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λ⁵-Phosphorus-Containing α-Diazo Compounds: A Valuable Tool for Accessing Phosphorus-Functionalized Molecules

λ⁵-Phosphorus-Containing α-Diazo Compounds: A Valuable Tool for Accessing Phosphorus-Functionalized Molecules