C-60 acts as a mechanistic probe for the formation of carbene, diazo compound, and for the rearranged product via the excited state in the photolysis of 3-chloro-3-isopropyldiazirine and 3-chloro-3-chloromethyldiazirine. The carbene adds to C-60 to form methanofullerene, whereas the diazo compound a...

Laser Flash Photolysis of arylchlorodiazirines in isooctane/CH2Cl2 in the presence of substituted vinylpyridines yields substituted vinylpyridinium ylide (lambda = 540 nm). As the ylide decays a concomitant growth causes an absorption at 330 nm, attributed to the formation of substituted indolizine....

Substituted pyrazoles and pyrrolo[1,2-c]pyrimidines were prepared from the reaction of arylchlorocarbenes with 1,2-diazabuta-1,3-dienes and 4-vinylpyrimidines, respectively.

1,2,3-Trisubstituted pyrroles have been synthesized in good yield from the reaction of chlorocarbenes with 1-azabuta-1,3-dienes.

By employing C-60 as a chemical probe, the photolysis of benzylchlorodiazirine has been proposed to form carbene and the rearranged products via the excited state. (c) 2006 Elsevier Ltd. All rights reserved.

C-60 acts as a mechanistic probe for the formation of carbene and for the rearranged product via the excited state in the photolysis of 3-t-butyl-3-chlorodiazirine. (C) 2004 Published by Elsevier Ltd.

The analysis of the time-resolved UV-vis absorption spectra of the 2-vinylpyridinium ylide of phenylchlorocarbene, measured by laser-flash photolysis, indicates the existence of two rotamers of this species. The absorption spectrum, rise time, and decay time of each rotamer were determined by a glob...

The photolysis of m-phenylene-bis(chlorodiazirine) in the presence of 2-vinylpyridine (VP) yields the m-phenylene-bis(indolizine) by a mechanism involving two consecutive photoreactions. Photolysis of a first diazirine ring generates a carbene which reacts with 2-VP to give, via a sequence of fast t...

Reaction of adamantylidene and phenylcarbene with ethylthiol, ethylene dithiol, allylethylsulfide, allylphenylsulfide, and trimethylenesulfide involves the formation of a sulfur ylide intermediate, followed by H-migration, 2,3-sigmatropic shift, or ring opening to give sulfides. The sulfur ylide for...

Reaction of arylchlorodiazirines with trimethylenesulfide gives a mixture of aryldi(3-chloropropyl)thioacetal and aryl(2-propenyl)(3-chloropropyl)thioacetal in a good yield. The reaction goes through a formation of a sulfur ylide as an intermediate. Rate constants have been determined using laser fl...

The formation of a metastable carbene-diazirine ylide (CDY), characterized by an UV absorption spectrum in the range of 270-290 nm and yielding azine by rearrangement, is shown to be a general process in the photolysis of diazirines. However, the yield of formation and the lifetime of CDY greatly de...

2,2'-Pyridyl- and 2,2'-thienylpyrroles containing substituents at the 1- and 3-positions of the pyrrole ring have been prepared from the reaction of heteroarylchlorocarbenes with 1-azabuta-1,3-dienes. Laser flash photolysis of heteroarylchlorocarbene in isooctane in the presence of 1-azabu...

The reactions of the singlet methylene (la) and dimethylcarbene (1b), with their diazirine precursors, diazirine (2a), and dimethyldiazirine (2b), have been studied theoretically using ab initio and density functional theory. The reaction has no activation barriers for the parent system (la + 2a) an...

An ultraviolet photoelectron (PE) spectrometer apparatus that utilizes a tuneable 50 W CW CO2 laser as a directed heat source was used to study the vacuum pyrolysis of diazoacetophenone (la) and its p-methyl, p-methoxy, p-chloro, and p-nitro analogues Ib, Ic, Id, and le. Analysis of the pyrolysate w...

Rearrangements of 2-adamantene 3, adamantylidene 4, and 4-protoadamantylidene 5 have been studied theoretically using high level ab initio computations. Adamantene 3 and adamantylidene 4 have singlet ground states. The conversion of 3 into 4 via 1,2 hydrogen migration (Delta G(not equal) = 69.1 kcal...

N-Protonated diazomethanes have been generated successfully via gas phase protonation of the corresponding diazirines.