A Laser Flash Photolysis Study of 2-Naphthyl(carbomethoxy)carbene

Wang, Jen-Lung; Likhotvorik, and Igor; Platz, Matthew S.

doi:10.1021/ja983279g

Cited by 43 publications

(53 citation statements)

References 49 publications

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“…3 , 4 , 5 , 11 , 12 or 13 ). 13 , 23 Alternatively, at this point, it is not possible to rule out that the excited diazocompound 1 1 * could react directly with a trapping partner to afford the corresponding final product. 24 Although inter system crossing (ISC) converting 1 18 to 3 18 is generally a fast process, in this case, experimental evidences suggest that this is a reversible event.…”

Section: Resultsmentioning

confidence: 99%

Blue light-promoted photolysis of aryldiazoacetates

2018

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Section: Resultsmentioning

confidence: 99%

Blue light-promoted photolysis of aryldiazoacetates

2018

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“…Thus carbonyl carbenes, R 1 COϪCϪR 2 , can be detected by UV/Vis spectroscopy if R 2 ϭ Ar but not if R 2 ϭ H, alkyl, or COR. Lifetimes of methoxycarbonyl(phenyl)carbene [163] (generated by LFP of 69) and methoxycarbonyl(2-naphthyl)-carbene (162) [164] were measured, but contributions of the Wolff rearrangement, if any, to the rates of carbene decay could not be assessed.…”

Section: Laser Flash Photolysis (Lfp)mentioning

confidence: 99%

100 Years of the Wolff Rearrangement

2002

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The conversion of α‐diazo ketones into ketenes, and products derived therefrom, was discovered by Wolff in 1902. Major applications of the Wolff rearrangement, such as the Arndt−Eistert reaction (homologation of carboxylic acids) and the ring contraction of cyclic ketones, have been with us for some while. Nevertheless, substantial progress has been made recently. The reaction mechanism has been explored by means of matrix isolation, time‐resolved spectroscopy, and computation. Full retention of configuration of the migrating group has been established by using enantioselective chromatography. The Arndt−Eistert reaction has witnessed a renaissance in the field of natural products, in particular β‐amino acids and β‐peptides. Ring‐contracting Wolff rearrangements and ketene cycloadditions have been applied in syntheses of increasingly complex, biologically active target molecules. These accomplishments, as well as unsolved problems, are addressed in the present review. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

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“…As observed in the case of diazomalonic acid esters where the conformational effect seems to have a strong influence on the reaction mechanism, a similar effect can be observed for simpler carboethoxycarbenes but in this case, the carbene substituents will strongly dictate the extension of ketene formation. For instance, in a remarkable work developed by Platz, it was observed that the photolytic decomposition of the simple ethyl diazoacetate [61] 15 (R=Et), and 2-naphthyl(carbomethoxy)carbene [62] (which was also observed by Toscano [63]), lead predominantly for the formation of a carbene species that reacts indiscriminately with alcohols, ethers, and alkenes. However, in a previous work reported by Tomioka,[64] the photolysis of methyl diazoacetate 15 (R=Me) was observed to produce an excited singlet state 15* that could suffer Wolff rearrangement competing with singlet carbene formation or intersystem crossing to the triplet diazo compound 3 15* (Scheme 14).…”

Section: Scheme 13mentioning

confidence: 98%

“…[135] Oxide products have been detected as contaminants in several other studies due to this same reaction of triplet carbene with triplet oxygen. [54,62,136]…”

Section: Reaction With Molecular Oxygenmentioning

confidence: 99%

Developments in the Photochemistry of Diazo Compounds

Candeias¹,

Afonso

2009

COC

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This review focus on photolytic reactions of diazo compounds, covering mainly synthetic applications such as Wolff rearrangement, 1,2-shift, X-H insertion, cyclopropanation, hydrogen abstraction and reaction with oxygen and physical organic studies, with special relevance to mechanistic considerations. the synthesis of a diazo compound if loss of a proton from the C()-atom of the primarily formed alkanediazonium ion is faster than the loss of dinitrogen, which makes this method almost specific for the case of aliphatic amines containing a C()-atom substituted by an acidifying group. Diazo compounds can also be prepared by acylation or cleavage of aliphatic diazo compounds containing the structural requirements. For instance, diazo carbonyl carbamate 4 can be prepared through the reaction of the carboxylate precursor with a chloroformate and further reaction of the anhydride with diazomethane (Scheme 2).[13] Making use of oxidants, diazo carbonyl compounds can be prepared by hydrazone oxidation in the presence of mercury oxide and potassium hydroxide.[14] Scheme 1 Scheme 2 Diazo-transfer reactions have been widely used since they are a more general method for the preparation of diazo compounds. In this reaction, the diazo moiety is transferred from the donor to an acceptor where the donor is a sulphonyl azide (6) and the acceptor a carbanion formed after deprotonation (Scheme 3).[3,15] Scheme 3 Diazo compounds can be submitted to several reaction conditions and myriads of compounds can be obtained by the proper choice of conditions and reagents. In the absence of a metal catalyst, this decomposition can be induced by thermolysis or photolysis, generating a highly reactive intermediate species that, in most cases, affords a complex mixture of products. Depending on the diazo compound and the reaction conditions, the resulting products can be derived from C-H or X-H

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A Laser Flash Photolysis Study of 2-Naphthyl(carbomethoxy)carbene

Cited by 43 publications

References 49 publications

Blue light-promoted photolysis of aryldiazoacetates

Blue light-promoted photolysis of aryldiazoacetates

100 Years of the Wolff Rearrangement

Developments in the Photochemistry of Diazo Compounds

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