SMART RUTHENIUM CATALYSTS FOR THE SELECTIVE CATALYTIC TRANSFORMATIONSOF ALKYNES

Easy to produce and to handle ruthenium catalyst precursors have been used for the activation of a variety of terminal alkynes. The anti-Mar kovnikov addition is performed in the catalytic synthesis of vinylcarb amates from terminal alkynes, CO2 and secondary amines via ruthenium v inylidene species, with catalysts of type RuCl2(PR3)(arene) (A) and th at of carboxylic acids to alkyl-Ce=CH, aryl-C=CH, HC=C-C(Me)=CH2 and H C=C-CH=CHOMe is performed by catalyst Ru(eta(3)-CH2C(Me)CH2)(2)(Ph2P(C H2)(n)PPh2) F-4(n = 4) to produced (Z)-alkn-1-yl eaters, whereas the u se of catalyst F-2(n = 2) is necessary to reach high regioselectivity in the formation of (Z)-alken-1-yl esters from HC=C-SiMe3 and HC=CCR2O Me. By contrast the latter (F-2) allows the isomerisation of HC=CCR2OH compounds into unsaturated aldehydes O=CH-CH=CR2 and the reaction is shown to proceed via an anti-Markovnikov adduct. The use of electron-r ich complex, containing a labile (cod) ligand, RuCl(cod)(C5Me5) (G) of fers the regioselective coupling C-Cof allyl alcohol with alkynes to p roduce gamma,delta-unsaturated aldehydes and with propargylic alcohols to afford 5-methylene tetrahydropyrane derivatives.