The present invention provides a method of preparing a phosphonium salt of
the formula [R.sup.1R.sup.2R.sup.3P--CR.sup.4R.sup.5R.sup.6]X, comprising
ball-milling a phosphine of the formula R.sup.1R.sup.2R.sup.3P with a
compound of the formula XCR.sup.4R.sup.5R.sup.6; a method of preparing a
phosphorus ylide of the formula
R.sup.1R.sup.2R.sup.3P.dbd.CR.sup.4R.sup.5, comprising ball-milling a
phosphonium salt of the formula
[R.sup.1R.sup.2R.sup.3P--HCR.sup.4R.sup.5]X in the presence of a base;
and a method of preparing an olefin of the formula
R.sup.4R.sup.5C.dbd.CR.sup.7H or R.sup.4R.sup.5C.dbd.CR.sup.7R.sup.8,
comprising ball-milling a phosphorus ylide of the formula
R.sup.1R.sup.2R.sup.3P.dbd.CR.sup.4R.sup.5 with a compound of the formula
R.sup.7C(O)H or R.sup.7C(O)R.sup.8. The inventive method produces
phosphonium salts and phosphorus ylides by mechanical processing solid
reagents under solvent-free conditions. The advantages of the present
invention over conventional solution methods, include: (1) extremely high
selectivity; (2) high yields; (3) low processing temperatures; (4) simple
and scalable reactions using commercially available equipment; and (5)
the complete elimination of solvents from the reaction.
