The reaction of the ortho-, meta-, and para-bis(triflates) the corresponding ferracyclophanes are formed only in situ.[ (F,CS020CH,CH2C,H,),(CH2)n] with n = 0 (ortho: l a ) , n = Carbon monoxide insertion into the Fe-C r s bonds of the fer-0, 1 (meta: lb, d), and n = 0-2 (para: lc, e , g) with racycles affords the ketones 6a, b. The structures of 2a and [OS(CO),]~-results in the formation of the diosrna[5.nS.n]-2e were investigated by X-ray structural analysis. Comortho-, -meta-, and -paracyclophanes with n = 0 (ortho: 2a), pounds 2a and 2e crystallize in the space group P2,/c with R = 0, 1 (meta: 2b, d), and n = 0-2 (para: 2c, e, 9). On reac-Z = 8 and P i with Z = 2, respectively. tion of the bis(trif1ates) l a , b with the dianionic [Fe(CO),]'-Metallacycloalkanes with at least two metal-carbon CF bonds serve as model compounds in transition metal-catalyzed or mediated organic syntheses, where they appear as reactive intcrmediates [1][2][3]l. An easy access to metallacycloalkanes has been opened by the bis(triflate) r~u t e [~.~-~] , which is a variant of cationic alkylation[81. The excellent and inert leaving group F,CS020-stabilizes carbenium-like atoms at the ends of a hydrocarbon chain[l01, thereby enabling an elcctrophilic attack of the terminal carbon atoms at a basic metal center. For instance, metallacycloalkanes of iron, ruthenium, and osmium with various ring sizes are available by the reaction of the corresponding bivalent metalates [M(CO)4]2-(M = Fe, Ru, 0 s ) with alkanediylbis(trifluoromethanes~lfonates)[~~~~~-~l. The use of bistriflates with a xylidene framework leads to metallacyclophanes as products following the bistriflate r o~t e [~,~l .Thus, a connection was established between the chemistry of metallacycloalkanes and that of cyclophanes. Cyclophane chemistry is undergoing rapid development and has produced a multitude of architecturally impressive molecules, with features related to structure and functionalization, that are able to embed guest molecules [' l]. The specific integration of heteroatoms (N, 0, S) leads to cyclophane frameworks with special complexation qualities, suitable for molecular recognition.The introduction of a tetracarbonyl transition metal moiety has an influence on the structure of the metallacyclophane because of the steric requirement. Simultaneously, a new reactive center is obtained that is capable of inserting carbon monoxide into the M-C CF bonds. A cyclic ketone is formed easily by reductive elimination of the organometallic fragment [ In this article we describe the preparation and properties of diosma[5.n.5.n]ortho-, -meta-, and -paracyclophanes with n = 0-2 and the reaction of the corresponding ferracyclophanes with carbon monoxide.
Results and Discussion
Diosmac yclophanesThe diosma[5.n.5.n]cyclophanes (n = 0-2) 2a-g, being made of two equivalent -[CH2I2-C6H4-[CH21n-C6H4-[CH2I2-Os(C0),-building blocks, are formed by treating the corresponding bis(triflates) la-g[14] with a suspension of the metal Lewis base [0s(CO),l2-in dimethyl ether at -30°C (Scheme I)....
