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Book Review Nitrogen Oxygen and Sulfur Ylide Chemistry Edited by J.

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Nitrogen, Oxygen and Sulfur Ylide
Edited by J. Stephen
Clark. (Series: Practical Approach in
Chemistry.) Oxford
University Press,
Oxford 2002. xiii þ
297 pp., hardcover
£ 80.00.—ISBN
Although less well known than the
phosphorus ylides, ylides containing
nitrogen, oxygen, and sulfur have been
the subject of increasing interest over
the last 30 years. Although these reactive intermediates are seldom isolable,
processes whereby they are generated
and subsequently react by cycloaddition
or sigmatropic rearrangement have
been used in many syntheses, and their
use might be said to have joined the
category of “standard methods” in many
cases. This book which offers a fairly
comprehensive treatment of the area is
thus welcome, the more so since, as part
of the Practical Approach in Chemistry
series, it includes fully detailed experimental procedures for selected methods.
The book begins with a detailed
overview of all the major classes of N,
O, and S ylides by J. S. Clark (113 pp.)
with over 300 references, many of them
composite. This is clearly presented with
thorough coverage of the literature up
to 2000, and deals in turn with ammonium, oxonium, sulfonium and oxosulfonium, azomethine, carbonyl, thiocarbonyl, and nitrile ylides.
The remainder of the book then
consists of 21 separate sections covering
specific topics, divided up according to
both the type of ylide and its method of
Angew. Chem. Int. Ed. 2003, 42, 969 – 971
generation. These are written by 16
different authors or teams of authors
including many, if not most, of the
leading authorities in the field. The
only curious feature of the coverage is
an apparent duplication, with the generation and reaction of isom.nchnones
forming the topic of both Chapters 3.9
and 3.10 (by different authors). The
individual contributions contain concise
and authoritative accounts of the state
of the art in each area, with references to
relevant reviews as well as the most
important papers in the primary literature, in some cases up to 2001. The really
distinctive feature of books in this series,
however, is the inclusion in each chapter
of fully detailed experimental procedures or “protocols”, each listing the
required equipment and starting materials and giving step-by-step instructions. These are sufficiently detailed to
allow the nonexpert to try out any
method and thus evaluate it for application to his or her own particular
problem. A useful feature is that,
where several stages are necessary to
get from a readily or commercially
available starting material to the product, these are all included. It might be
noted that no fewer than 44 out of the 67
protocols listed require column chromatography to obtain the final product,
thus suggesting that the methods are
perhaps more suitable for small-scale
total synthesis rather than practical synthesis of products on a large scale.
In this era of increasing awareness of
health and safety issues, I suppose we
should expect the inclusion of risk
phrases for each item in the lists of
starting materials. However, it is unfortunate that this has apparently been
done independently by each author with
the result that there are numerous discrepancies. Thus, for example, diethyl
ether is listed variously as “flammable”,
“flammable, irritant”, and “toxic, flammable”, hexane as “flammable”, “toxic,
2 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
flammable”, “flammable, irritant”, and
“harmful, flammable”, and ethyl acetate
as “flammable”, “irritant, flammable”,
or with no risk phrase, depending on
which protocol one consults. In view of
the limited number of substances
involved, it would have been better for
the editor to have inserted these uniformly from an authoritative list such as
that produced by the United Nations.
More seriously, there is a danger that the
blanket assignment of risk phrases may
lead to an air of complacency and
disguise the really hazardous materials.
Thus, while adequate warnings are given
for the preparation of chloromethyl
methyl ether and bis(chloromethyl)
ether in Chapter 3.8, the phrase
“cancer suspect agent” is applied elsewhere to paraformaldehyde, dichloromethane, chloroform, methyl iodide,
and benzene, without any indication of
the degree of suspicion in each case, and
on page 224 sodium hydroxide is described as “toxic, carcinogenic”! Interestingly, many of the protocols involving
diazo compounds are carried out in
benzene, but with a curious footnote
which might be taken to mean that the
authors realize that they should have
tried the safer alternative of toluene but
in fact did not.
The volume concludes with an adequate index. Overall the presentation is
clear and uniform, which is no small
achievement for a volume with contributions from 17 different author teams.
The book provides a well-balanced and
up-to-date coverage of the area which is
not readily available from any other
single source, and will be of interest to
all who wish to consider applying N-, O-,
and S-based ylides in their research.
R. Alan Aitken
School of Chemistry
University of St Andrews (UK)
0044-8249/03/4209-0971 $ 20.00+.50/0
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chemistry, book, nitrogen, sulfur, edited, ylide, review, oxygen
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