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Current Organic Synthesis
ISSN: 1570-1794 - Volume 3, 4 Issues, 2006
Current Organic Synthesis
Volume 3, Number 1, February 2006
Contents
Synthetic Approaches for the Nanoencapsulation
of Fullerenes Pp. 1-7
C.N. Murthy and K.E. Geckeler
[Abstract]
Cycloadditions as a Method for Oligonucleotide Conjugation
Pp. 9-17
D. Graham and A. Enright
[Abstract]
The Higher Oligopyridines and their Metal Complexes
Pp. 19-39
Reza-Ali Fallahpour
[Abstract]
Asymmetric Synthesis of Styryl-Lactones Pp.
41-75
M. Mondon and J.-P. Gesson
[Abstract]
Asymmetric Synthesis of Cyanohydrins Pp.
77-97
Fu-Xue Chen and Xiaoming Feng
[Abstract]
Syntheses of Morphine and Codeine (1992 – 2002):Templates
for Exploration of Synthetic Tools Pp. 99-120
L.M. Mascavage, M.L. Wilson and D.R. Dalton
[Abstract]
Abstracts
[Back to top]
Synthetic Approaches for the Nanoencapsulation of
Fullerenes
C.N. Murthy and K.E. Geckeler
Encapsulation of [60]fullerene by cyclic molecules like
cyclodextrins and calixarenes has many different applications.
One of the earliest among them was to enhance the solubility
of [60]fullerene in both polar as well as non-polar solvents
and this has had immense application potential in materials
research and medicine. Molecular modeling studies are efficient
tools to study the supramolecular structures and have the
advantage of predicting the structures even before carrying
out an experiment. Unlike the naturally occurring cyclodextrins
that cannot be easily obtained by a totally synthetic procedure,
calixarenes are the product of the condensation reactions
between para-substituted phenols and formaldehyde. These bowl-shaped
molecules have cavities that can hold metals as well as molecules
and have been used to sequester metal ions. This review highlights
the research done in the nanoencapsulation of fullerenes by
cyclodextrins and calixarenes during the last decade and looks
at the emerging trends in this area.
[Back to top]
Cycloadditions as a Method for Oligonucleotide Conjugation
D. Graham and A. Enright
There is a large requirement in modern molecular biology
for the production of specifically conjugated oligonucleotides.
For instance, oligonucleotides may be conjugated to fluorescent
labels to allow sequence specific detection following a biological
assay. A number of methods exist for the conjugation of oligonucleotides
and mainly rely on the use of a nucleophile attached to the
oligonucleotide reacting with reactive species to form the
desired product. A new approach to achieve oligonucleotide
conjugations is to use cycloadditions. This review covers
the growing use of cycloadditions for labelling of oligonucleotides
at various positions within the sequence and the advantages
over existing techniques. A number of different dienes have
been reported and each is reviewed. Finally, the use of these
conjugated oligonucleotides is reported with a view, to demonstrate
the advantages of using cycloaddition for the conjugations.
[Back to top]
The Higher Oligopyridines and their Metal Complexes
Reza-Ali Fallahpour
The series of oligopyridine ligands has increasingly become
one of the most popular ligands in coordination chemistry.
While the lower members of this series, 2,2’-bipyridine
(bpy) and 2,2’:6’,2’’-terpyridine
(tpy), are mostly used due to their easy synthetic accessibility
and predictable coordination behaviour, the higher members
have also attracted chemists’ interest. The higher the
number of pyridine ring is, the lower is the solubility. Though
some aromatic rests were attached to pyridine rings to increase
the solubility. In addition, the higher oligopyridines may
react, depending on metal ions, in different manners, e.g.
they can be divided into subunits. This may be a drawback,
however, this property was used to prepare fascinating metal
complexes. These two properties make them as attractive and
challenging synthetic molecules for chemists and material
scientists.
In this paper the synthetic strategies used to prepare the
higher oligopyridine ligands are reviewed comprehensively.
[Back to top]
Asymmetric Synthesis of Styryl-Lactones
M. Mondon and J.-P. Gesson
A small, but extraordinary diverse class of bioactive styryl-lactones
has been isolated from several species of the genus Goniothalamus
(Annonnaceae). The interesting biological properties, in particular
antitumoral, and structural diversity of these lactones have
prompted several asymmetric syntheses. They may be classified
in two types: synthesis from enantiomerically pure material
(carbohydrate…) or with asymmetric methodologies (dihydroxylation,
epoxidation…). This review will discuss the different
strategies implemented to prepare these styryl-lactones.
[Back to top]
Asymmetric Synthesis of Cyanohydrins
Fu-Xue Chen and Xiaoming Feng
Catalysts and cyanide sources for asymmetric synthesis of
cyanohydrins are reviewed with 175 references.
[Back to top]
Syntheses of Morphine and Codeine (1992 – 2002):Templates
for Exploration of Synthetic Tools
L.M. Mascavage, M.L. Wilson and D.R. Dalton
Morphine (1) and its O-methylated analogue
codeine (2), analgesic alkaloids of the opium
poppy (Papaver Somniferium), have been targets of
organic chemists engaged in synthetic activities for at least
half a century. The “first” (Gates) and “most
efficient” (Rice) syntheses of morphine (1)
and codeine (2) are well known and have been
reviewed and analyzed extensively numerous times. However,
syntheses of the same two alkaloids that have been reported
since 1992 and which have been used as devices to advance
the art of organic synthesis are not as widely recognized
and they have not been as thoroughly reviewed. Here they are
analyzed in the spirit of the use of these two compounds as
templates. Further, since both racemic and enantiospecific
syntheses are important and since all eight (8) approaches
(since 1992) are sufficiently different so as to warrant more
tha n superficial examination, they are all considered.
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