SOLVENT-FREE MECHANOCHEMICAL PREPARATION OF PHOSPHONIUM SALTS, PHOSPHORUS YLIDES, AND OLEFINS

摘要

The present invention provides a method of preparing a phosphonium salt of the formula [R1R2R3P-CR4R5R6]X, comprising ball-milling a phosphine of the formula R1R2R3P with a compound of the formula XCR4R5R6; a method of preparing a phosphorus ylide of the formula R1R2R3P=CR4R5, comprising ball-milling a phosphonium salt of the formula [R1R2R3P-HCR4R5]X in the presence of a base; and a method of preparing an olefin of the formula R4R5C=CR7H or R4R5C=CR7RB, comprising ball-milling a phosphorus ylide of the formula R1R2R3P=CR4R5 with a compound of the formula R7C(O)H or R7C(O)R8. 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.