Mini-Reviews in Organic Chemistry, Volume 1, No. 4, 2004
Contents
Advances in the Chemical Synthesis of
Medium-Sized Cyclitols Pp.343-357
Inhibitors Targeting the Enzymatic Activity
and Biological Function of Pin1 Pp.359-366
Yixin Zhang
Thienothiophenes: Synthesis and Applications Pp.367-374
A. Comel, G. Sommen
and G. Kirsch
Synthesis of 1, 2, 4-Triazoles and Thiazoles
from Thiosemicarbazide and its Derivatives Pp.375-385
Suni M. Mustafa, Vipin
A. Nair, Joshua P. Chittoor and Sreekumar Krishnapillai
Use of β-(N,N-dialkylamino)Propiophenones
in the Synthesis of Nitrogenated Heterocyclic Compounds Pp.387-402
R. Abonia, B.
Insuasty, J. Quiroga, M. Nogueras and H. Meier
Quinone Methides as Alkylating and
Cross-Linking Agents Pp.403-415
Mauro Freccero
Preparation of Fluorine-Containing
Heterocyclic Compounds via Cycloaddition Reactions Pp.417-435
P. He and S.Z. Zhu
Abstracts
[Back to top] Advances
in the Chemical Synthesis of Medium-Sized Cyclitols
Gloria Rassu, Luciana Auzzas, Lucia Battistini and Giovanni Casiraghi
Densely hydroxylated, medium-sized
carbocycles and their analogues have long been a somewhat neglected molecular
progeny for two reasons: (a) the synthesis of such expanded and functionality
rich rings is quite a challenging task that remains partially unsolved and (b)
the biological significance of these constructs has not yet been thoroughly
appreciated. This account mainly discusses recent approaches used to deal with
this rare class of carbohydrate mimics with particular emphasis being placed on
annulative strategies using ring-closing metathesis, aldol-based ring closure,
intramolecular nitrile oxide and nitrone cycloaddition, and the Claisen
rearrangement. Less documented annulative and non-annulative procedures
including free-radical cyclisation, intramolecular coupling, and ring expansion
and manipulation are also considered.
[Back to top] Inhibitors
Targeting the Enzymatic Activity and Biological Function of Pin1
Yixin Zhang
Pin1, a phospho-Ser/Thr-Pro specific PPIase,
participates in many biological processes. Recently, through designing
substrate mimetics, or library screening, several classes of Pin1 inhibitors
have been discovered. Some polyaromatic compounds, including juglone, as well
as peptide mimetics containing both proline and phosphate, have been demonstrated
to inhibit biological functions of Pin1.
[Back to top]
Thienothiophenes:
Synthesis and Applications
A. Comel, G. Sommen
and G. Kirsch
The four isomers of thienothiophene have long
been considered only for academic interest. Their usefulness in material
science and biology has led to a renewal of their chemistry. The present paper
reports the newest synthetic methods after the first review by Litvinov and
Gol’dfarb in 1976.
[Back to top]
Synthesis of 1,
2, 4-Triazoles and Thiazoles from Thiosemicarbazide and its Derivatives
Suni M. Mustafa, Vipin A. Nair, Joshua P. Chittoor and Sreekumar Krishnapillai
The use of thiosemicarbazide in organic
synthesis has become a classical strategy for the synthesis of several
heterocycles. Their reactions with compounds containing C=O and C=N groups is an
elegant method for the preparation of biologically active compounds viz.
triazoles and thiazoles. The ease of forming C-N and C=N bonds as opposed to
N-N bond formation is reflected in their extensive use for the preparation of
these heterocycles. As the internal nitrogen atom of the hydrazine fragment is
a softer nucleophilic centre than the more powerful terminal nitrogen, reagents
susceptible to nucleophilic attack by the terminal nitrogen undergo cyclisation
to afford the aforesaid heterocycles in excellent yields, even under mild
reaction conditions. The present review attempts to summarise the cyclisation
reactions of thiosemicarbazide derivatives yielding 1, 2, 4-triazoles and
thiazoles.
[Back to top]
Use of β-(N,N-dialkylamino)Propiophenones
in the Synthesis of Nitrogenated Heterocyclic Compounds
R. Abonia, B.
Insuasty, J. Quiroga, M. Nogueras and H. Meier
β-(N,N-dialkylamino)propiophenones
(ArCOCHR1CH2NR2) are compounds with special
synthetic interest not only because many of them are biologically active, but
also because they posses two different electrophilic reaction centers (i. e.
carbonyl group and the β-carbon atom), which can be attacked by
ambifunctional nucleophilic reagents. This property makes them attractive
starting materials in medicinal chemistry as valuable building blocks for ring
closure reactions to form mainly five, six and seven-membered heterocyclic
compounds. Additionally, the presence of α-methylene active hydrogen atoms
in such compounds also opens new possibilities for ring closure reaction as
recently has been published. A selection of representative examples about
structural and biological properties of the title compounds, synthetic methods
and ring closure reactions leading to nitrogenated heterocyclic systems are
described in this review.
[Back to top]
Quinone
Methides as Alkylating and Cross-Linking Agents
Mauro Freccero
Quinone methides (QMs) are reactive
intermediates involved in a large number of chemical and biological processes
such as enzyme inhibition, DNA alkylation and cross-linking. Their
electrophilicity towards amines, thiols, water, amino acids and peptides has
been kinetically measured in aqueous solution. The alkylation process is often
thermally and photochemically reversible and the resulting adducts may act as
QM carriers.
[Back to top]
Preparation of Fluorine-Containing
Heterocyclic Compounds via Cycloaddition Reactions
P. He and S.Z. Zhu
This account deals with recent progress in
the study on the synthesis of fluorine containing heterocycles via the
cycloaddition reactions of some fluorine-containing dienophiles or
dipolarophiles. It includes two main parts: (1) the 1,3-dipolar cycloaddition
reactions to five-membered fluorinated heterocycles; (2) the (hetero)
Diels-Alder reactions to six-membered fluorinated heterocycles.