Phospholes Synthesis

McCORMACK-KUCHTIN-RAMIREZ Phosphole Synthesis Formation of phospholes from butadienes (McCormack) or of dioxaphospholes from 1,2-diketones (Kuchtin-Ramirez), (see 1st edition). 

Fbnmtwnofphosph, UCHT,N HAM,REZ Phosphole Synthesis diketones (Kuchtm-Ran, bU KW ° ° dloxapbospholes, rom 1>... 

Phosphine oxides are normally reducible to the phosphines with trichlorosilane or phenylsilane (Equation (31)), and some examples with cyclic systems have recently been reviewed . This reaction probably can be applied to the stable phosphole oxides, and would have practical value as a phosphole synthesis when applied to phosphole oxides that are prepared by methods other than the direct oxidation method. 

Construction of the phosphole ring, with one useful exception, is accomplished by methods that are quite different from those employed for the N, S, O ring systems. Because of fundamental differences in the chemistry of phosphines versus amines, none of the familiar carbonyl condensation processes are known to be applicable to phosphole synthesis. Thus an attempt to use the Paal-Knorr condensation of 1,4-dicarbonyl compounds with PhPH2 <65JCS2184> and with PH3 <88ZOB783> failed to give phospholes. The only successful method known to the present that is common to both the phosphole and pyrrole ring systems is the condensation of 1,3-diynes with primary phosphines... 

A discovery in phosphole synthesis in 1988 is that reacting a mixture of two moles of an enamine with a phosphonous dichloride at room temperature results in a one-step construction of the phosphole ring, bearing an amino substituent <88TL458l>. This reaction is considered in more detail in Section 2.15.12.5 treating functional phospholes it constitutes an important advance in this area, and is the only source at present of aminophospholes. Further development of the method could make it of major significance in phosphole chemistry. 

C. Charrier, H. Bonnard, G. de Lauzon, and F. Mathey, ]. Am. Chem. Soc., 105, 6871 (1983). Proton [1,5] Shifts in Phosphorus-Unsubstituted IH-Phospholes. Synthesis and Chemistry of 2H-Phosphole Dimers. 

Sauthier M, Leca F, Toupet L, Reau R (2002) Palladium eomplexes of a uovel family of P,N-chelates, the 2-(2-pyridyl)phospholes synthesis, struetirral ehaiacterization, and catalytic activity for olefin/CO copolymerization. Organometallics 21 1591... 

Charrier C, Bonnard H, de Lauzon G, Mathey F (1983) Proton [1,5] shifts in P-unsubstituted IH-phospholes—synthesis and chemistry of 2H-phosphole dimers. J Am Chem Soe 105 6871... 

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