Table Of ContentOrganophosphorus Chemistry
Volume 22
A Specialist Periodical Report
Organophosphorus
Chemistry
Volume 22
A Review of the Recent Literature Published
between July 1989 and June 1990
Senior Reporters
D. W. Allen, Sheffield City Polytechnic
B. J. Walker, Department of Chemistry, David Keir Building,
The Queen's University of Belfast
Reporters
C. W. Allen, University of Vermont, U.S.A.
R. Cosstick, University of Liverpool
0. Dahl, University of Copenhagen, Denmark
R. S. Edmundson, formerly of University of Bradford
C. D. Hall, King's College, London
ISBN 0-85 186-206-3
lSSN 0306-07 13
Copyright @ 1991
The Royal Society of Chemistry
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pcwnission .from The Rqval Society of Chernistn
Published by The Royal Society of Chemistry,
Thomas Graham House, The Science Park, Cambridge CB4 4WF
Printed in Great Britain by Billing & Sons Ltd.. Worcester
Introduction
Volume 22 introduces one of us, David Allen, as a new Senior Reporter,
although not as an author since David has contributed to Organophosphorus
Chemistry since volume 7. David replaces John Hobbs, who we thank for all
his hard work, not only as Senior reporter but also as author of the
"Nucleotides and Nucleic Acids" chapter. We have been fortunate in
persuading Rick Cosstick to take on the formidable task of writing this
chapter and we welcome him. Unfortunately we have again not been able to
include the "Physical Methods" chapter but we hope to do so next year.
A highlight of the year covered by this volume was the XIth
International Conference on Phosphorus Chemistry held in Tallinn, Estonia,
during July 1989. This was not only an unusual and most enjoyable
experience, it was also a most timely venue in view of the far reaching
developments in Eastern Europe. We met many old, and made many new,
friends and it is clear that the traditional strength of organophosphorus
chemistry in the USSR is safe in the hands of excellent young chemists with
modern ideas. We look forward to the XIIth International Conference at
Toulouse in 1992.
As measured by the numbers of publications the activity in all the
areas covered has increased. The interest in the px-bonded area has
increased again after last year's apparent decline. The results of a structural
study of bis(bory1)diphosphines indicate a P-P bond length in the range
normally reserved for P=P bonds. This suggests that the P-P bond
shortening in diphosphenes, which has always been interpreted as being
due to 3px-3px, may to some extent be a consequence of rehybridization.
There have been a number of developments worthy of special mention
in chemistry invoIving pentaco-ordinated compounds and intermediates.
These include reports of molecular mechanics calculations to study the
hydrolysis of cyclic phosphorus esters, further detailed studies of the
reactions of tervalent phosphorus compounds with acetylene carboxylates
and the first synthesis of a pentaco-ordinated phosphorus compound
containing a three-membered (phosphirene) ring. There has also been
further elegant work in the area of phosphatrane chemistry.
Novel phosphine oxide cage compounds have been prepared from
tris(4-hydroxypheny1)phosphine oxide and their structures have been
determined by X-ray crystallography. High temperature thermolysis of
vi lntroduction
dimethylphosphins oxide gives 2-phosphapropene via elimination of water;
this is perhaps surpesing since it involves loss of the P=O bond.
In tervalent phosphorus acid chemistry the main area of activity has
again been the use of tervalent phosphorus acid derivatives for the
preparation of phosphates or modified phosphates of biochemical interest.
Apart from the nucleotide field, (vide infra), pentavalent phosphorus acid
chemistry seems to be mainly in the doldrums; exceptions to this are the
areas of myo-inositol phosphate and aminoalkylphosphonate chemistry
where activity remains high.
It is gratifying to observe that the nucleotide field continues to
produce a large quantity of innovative phosphorus chemistry. The potential
use of anti-sense oligonucleotides to control gene expression is now widely
accepted and has been responsible for the explosive increase of activity in
the synthesis of modified oligonucleotides. However, if the anti-sense
therapeutic principle is going to fulfil its initial expectations and maintain
momentum, exciting and widely reproducible biological activity will have to
be demonstrated in the near future. Activity also remains high in the
synthesis of non-radiolabelled oligonucleotides for use as hybridization
probes. Many versatile procedures have been reported in the last year
which enable oligonucleotides to be labelled with multiple reporter groups
either during automated chemical synthesis or as a post-synthesis
modification.
Reports of the use in synthesis of the Wittig reaction, and the related
methods involving phosphonate and phosphine oxide carbanions and
iminophosphoranes, have, if anything, increased and many of these include
useful innovations. New results and speculation on the mechanism of the
Wittig reaction continue to be published by groups with well established
reputations in the area.
Activity in the phosphazene area has increased over that reported in
volume 21 as indicated by an increase of fifty-five in the number of
citations. Three particular areas deserve special mention. These are the use
of the aza-Wittig reaction in the construction of heterocyclic rings, the
structural diversity and solvent selectivity in macrocycles formed by
reactions of long chain diamines (or oxodiamines) with N3P3C16 and lastly
the synthesis of new heterophosphazene polymers by ring opening reactions
of cyclic he terophosphazenes.
D W Allen and B J Walker
Cont ent s
CHAPTER 1 Phosphines and Phosphonium Salts
By D.W. Allen
1 Phosphines 1
1.1 Preparation 1
1.1.1 From Halogenophosphines and
Organometallic Reagents 1
1.1.2 From Metallated Phosphines 3
1.1.3 By Addition of P-H to Unsaturated
Compounds 7
1.1.4 By Reduction 7
1.1.5 Miscellaneous Methods 9
1.2 Reactions 12
1.2.1 Nucleophilic Attack at Carbon 12
1.2.2 Nucleophilic Attack at Halogen 12
1.2.3 Nucleophilic Attack at Other Atoms 13
1.2.4 Miscellaneous Reactions 15
2 Halogenophosphines 16
2.1 Preparation 16
2.2 Reactions 17
3 Phosphonium Salts 19
3.1 Preparation 19
3.2 Reactions 21
4 p,-Bonded Phosphorus Compounds 23
5 Phosphirenes, Phospholes and Phosphinines 30
References 34
CHAPTER 2 Pentaco-ordinated and Hexaco-ordinated
Compounds
By C.D. Hall
Introduction 48
Structure, Bonding and Ligand Reorganization 48
Acyclic Phosphoranes 50
Ring Containing Phosphoranes 53
4.1 Monocyclic Phosphoranes 53
4.2 Eicyclic and Tricyclic Phosphoranes 59
...
Vlll Contents
5 Hexaco-ordinated Phosphorus Compounds 63
References 69
CHAPTER 3 Phosphine Oxide and Related Compounds
By B.J. Walker
Preparation of Acyclic Phosphine Oxides 71
Preparation of Cyclic Phosphine Oxides 71
Structure and Physical Aspects 74
Reactions at Phosphorus 77
Reactions at the Side-Chain 77
Phosphine Oxide Complexes 82
References 85
CHAPTER 4 Tervalent Phosphorus Acids
By 0. Dahl
1 Introduction 87
2 Nucleophillc Reactions 87
2.1 Attack on Saturated Carbon 87
2.2 Attack on Unsaturated Carbon 89
2.3 Attack on Nitrogen, Chalcogen, or Halogen 89
3 Electrophilic Reactions 92
3.1 Preparation 92
3.2 Mechanistic Studies 95
3.3 Use for Nucleotide, Sugar Phosphate,
Phospholipid or Phosphoprotein Synthesis 95
3.4 Miscellaneous 103
4 Reactions involving Two-co-ordinating
Phosphorus 106
5 Miscellaneous Reactions 106
References 110
CHAPTER 5 Quinquevalent Phosphorus Acids
By R.S. Edmundson
1 Phosphoric Acids and their Derivatives 114
1.1 Synthesis 114
1.2 Reactions 128
1.3 Uses of Phosphoric Acid Derivatives 133
2 Phosphonic and Phosphinic Acids and their
Derivatives 134
2.1 Synthesis 134
2.2 Reactions 161
References 174
