Phosphines reaction with epoxides

Synthesis of azindines Irom epoxides via amino alcohols or azido alcohols and reaction with phosphines or phosphites... 

One of the earliest chemical transformations of 1,2-dioxetanes was their reaction with phosphines (Eq. 72). It was shown that the trivalent phosphorus first inserts into the peroxide bond to afford a relatively stable phosphorane. On warming the phosphorane eliminates phosphine oxide to yield the epoxide product. In this elimination, there is inversion of the stereochemistry at one of the carbon centers. 

Singlet oxygen reacts with binaphthylphosphine derivatives such as 1, l -binaphthyldi-/-butylphosphine to form the corresponding binaphthyl-2-oxide phosphine oxides. This intramolecular arene epoxidation reaction proceeds with complete retention of stereochemistry. The binaphthyl-2-oxide di-/-butylphosphine oxide undergoes a slow NIH rearrangement to form the corresponding hydroxylated product. A transient phospha-dioxirane intermediate has been directly observed by low-temperature NMR.241... 

There have been extensive studies on the reaction of dioxetanes and dioxetanones with nucleophiles (C, N, P, and S) and the reader is directed to CHEC-II(1996) for an exhaustive list up to 1996. The most common reactions of dioxetanes have been with phosphorus nucleophiles. The phosphines and phosphites first insert into the 0-0 bond. The phosphorane intermediate then collapses to afford phosphine oxide or the trialkylphosphate and the corresponding epoxide (Scheme 6). The same is true for the treatment of a-peroxy lactones with phosphines and phosphites except that the so-formed a-lactone intermediate undergoes decarboxylation and ultimately furnishes a ketone <1997JOC1623>. 

Epoxides can be formed by treatment with phosphines [133a] via the corresponding phosphorane 138 (Sch. 78) [133b], and analogous reactions... 

Besides zinc, copper and nickel, numerous other transition metals show high activity in epoxide carboxylaiion, excellent catalysts being chromium, manganese, iron or cobalt compounds in the presence of organic halides 1227). Halides of ruthenium, rhodium or cadmium were also used with phosphines to accelerate the reaction velocity (210). Kisch found catalyst systems which are active, eip-en at room temperature and under ordinary pressure [228]. Tlie most cftective catalyst was the combination of triphenylphosphine and molybdenum pcntachloridc propylene carbonate was formed in a 78% yield. 

Aztridtnes. Epoxides can be converted into aziridines with overall retention of configuration by reaction with NaNs to form an azido alcohol (inversion), which is converted into an aziridine by reaction with a tertiary phosphine (inversion), equation (1). 

N-acylaziridines occurs on treatment with triphenylphosphine with the formation of the ylides (67), thereby providing a route to a-substituted primary allylic amines via their in situ reactions with aldehydes.The reactions of triphenylphosphine with epoxides in phenolic media provide a new access to the vinyl-phosphonium salts (68). A route to 1-hydroxyalkylphosphonium salts is provided by the reactions of trimethyl- or triethyl-phosphine with aldehydes or ketones in the presence of anhydrous acids. The related 1-trimethylsiloxyalkylphosphonium salts can be isolated in the presence of trimethylsilyl chloride.Further Wittig-products have been isolated from the reaction of 1,2,3-indanetrione with triphenylphosphine, and, in related work, it has been shown that furoin is deoxygenated on heating with triphenylphosphine to form 2-furfuryl(2-furyl)ketone and triphenylphosphine oxide.The structure of the blue product from the reaction of triphenylphosphine with 2,3,5,6-tetracyano-7-oxabicyclo(2,2,1]hepta-2,5-diene has now been shown by X-ray techniques to be the stable ylide (69). ... 

Phosphine and hydroxy groups emerge simultaneously and therefore subsequent reaction with the air-sensitive hydroxyphosphine can be avoided. The structure of the cyclic ether determines in each case the distance separating functional groups in the product this means epoxides form 1,2-hydroxyphosphines, 1,3-prod-ucts can be produced by the employment of oxetanes [5], etc. Problems may be caused by the formation of regio- and stereoisomeric byproducts during the ringopening step by application of internal nonsymmetric cyclic ethers [6],... 

Epoxides. Reaction pathways for the Mitsunobu reaction to convert l,l-diaryl-2-phenylethanediols to epoxides are phosphine-dependent. Retention of configuration at the secondary carbinolic center is observed in reaction mediated by PhsP-DIAD, while mote electron-rich phosphines (e.g., BU3P) favor products with inversion of configuration. ... 

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