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Stereochemistry of substitution at trico-ordinate phosphorus

Publikation: Forskning - peer reviewTidsskriftartikel

John Nielsen, Otto Dahl

A series of reactions of ring-substituted 1,3,2-dioxaphospholanes, 1,3,2-oxazaphospholanes, 1,2-oxaphospholes, and phosphetanes bearing the leaving groups Cl, OR, or NR2 on phosphorus, with the nucleophiles HCl, MeO-, MeOH, PhOH, Me2NH, Et2NH, and [CH 2]5NH have been studied. N.m.r. signals (1H and 31P) from reactant and product diastereoisomers have been assigned, and the stereo-chemistry of the substitution reactions have been determined by 31P n.m.r. monitoring. The outcome varies from complete inversion to complete lack of stereoselectivity. During the initial stages many of the non-selective reactions proceed with predominant inversion, and most of the results may be interpreted by assuming that the actual substitution step occurs with inversion, and that the lack of stereoselectivity is due to competing isomerizations of products or reactants. Exceptions are certain reactions where the leaving group is Cl; these appear to involve a non-selective substitution step.

OriginalsprogEngelsk
TidsskriftJournal of the Chemical Society, Perkin Transactions 2
Tidsskriftsnummer3
Sider (fra-til)553-558
Antal sider6
ISSN1472-779X
StatusUdgivet - 1 dec. 1984

ID: 131117193