Laser Flash Photolysis Studies of Triplet Carbenes

Platz, Matthew S.; Maloney, Vincent M.

doi:10.1007/978-1-4899-3707-0_8

Cited by 77 publications

(105 citation statements)

References 131 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pentane (Aldrich, HPLC grade), cyclohexane and acetonitrile (Burdick and Jackson, high-purity grade), and cyclohexane-d 12 (CIL, 99.7%) were used as received. Benzene was distilled from sodium/benzophenone.…”

Section: Methodsmentioning

confidence: 99%

Laser Flash Photolysis Study of Chlorocarbene

Robert¹,

Toscano²,

Platz³

et al. 1996

J. Phys. Chem.

Self Cite

View full text Add to dashboard Cite

Laser flash photolysis (308 nm) of endo-7-chlorodibenzo [a,c]bicyclo [4.1.0]heptane produces phenanthrene and chlorocarbene, which can be trapped with pyridine to form an ylide. The ylide absorbs strongly at 374 nm, and its lifetime is many tens of microseconds. It was not possible to resolve the grow of the ylide due to the rapid reaction of chlorocarbene with solvent. It was possible, however, to deduce the lifetimes of chlorocarbene in various solvents by measuring the yield of ylide as a function of [pyridine] and assuming that the absolute rate constant of reaction of chlorocarbene is the average of those of dichlorocarbene and alkylchlorocarbenes, which have been previously reported. Absolute rate constants for the reaction of chlorocarbene with alkenes were then deduced by the Stern-Volmer method, and the relative reactivity of chlorocarbene toward alkenes was found to be in good agreement with the relative reactivities of the lithiumchlorocarbene complex or carbenoid determined by analysis of product mixtures reported by Closs and Schwartz.

show abstract

Section: Methodsmentioning

confidence: 99%

Laser Flash Photolysis Study of Chlorocarbene

Robert¹,

Toscano²,

Platz³

et al. 1996

J. Phys. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Carbenes, for example, reach spin equilibrium in times usually of the order of 1 ns or less. 21,[52][53][54] The implication of this result, coupled with the assumption that the radical products derive from triplet state reactions, is either that 2g must be a groundstate triplet or that the singlet and triplet states must be close enough in energy that the singlet state can react via an equilibrium with the higher energy triplet. If the latter case were operative, we would have expected to observe some singlet products (i.e.…”

mentioning

confidence: 98%

Singlet and triplet states in the reactions of nitrenium ions

Falvey

1999

J. Phys. Org. Chem.

View full text Add to dashboard Cite

Nitrenium ions (R-N-R ) are reactive intermediates which are isoelectronic with carbenes. Like the more familiar carbenes, nitrenium ions have low-energy singlet and triplet states. Recent experiments have been directed at understanding how singlet and triplet nitrenium ions differ in their chemical reactivity. Singlet nitrenium ions typically react rapidly with nucleophiles whereas the triplet nitrenium ions tend to abstract H atoms. Several specific cases are discussed including the parent system, NH 2 , and several arylnitrenium ions.

show abstract

“…On the basis of the above experimental observations and previous literature reports, , a rational mechanism for this blue-light-mediated formal Doyle–Kirmse reaction is proposed in Scheme b. First, the phenyl diazoester 1a is activated to the excited state 1a* under the irradiation of blue light, which expels dinitrogen to produce a singlet carbene intermediate 1 A that can undergo intersystem crossing (ISC) to a less reactive ground triplet carbene 3 A .…”

mentioning

confidence: 99%

gem-Difluoroallylation of Aryl Diazoesters via Catalyst-Free, Blue-Light-Mediated Formal Doyle–Kirmse Reaction

et al. 2019

View full text Add to dashboard Cite

A first example of low-energy blue-lightmediated formal Doyle−Kirmse reaction for gem-difluoroallylation of aryl diazoesters has been developed. A variety of highly functionalized gem-difluoroallyl containing esters bearing transformable sulfur and bromine groups were efficiently assembled with broad substrate scope under mild, catalyst-free, and additive-free conditions. The reaction represents a practical and environmentally friendly approach for C−CF 2 bond formation based on rearrangement strategy, which will find potential applications among drug discovery and development.

show abstract

Laser Flash Photolysis Studies of Triplet Carbenes

Cited by 77 publications

References 131 publications

Laser Flash Photolysis Study of Chlorocarbene

Laser Flash Photolysis Study of Chlorocarbene

Singlet and triplet states in the reactions of nitrenium ions

gem-Difluoroallylation of Aryl Diazoesters via Catalyst-Free, Blue-Light-Mediated Formal Doyle–Kirmse Reaction

Contact Info

Product

Resources

About