Ferrocene ester

M. F. Czarniecki (13) also has examined the ferrocene ester (II) carrying a propiolic acid sidechain. This also fits very well, since the somewhat shorter distance involved with an acetylene makes up for the zig-zag arrangement of an olefin. He finds that the acceleration of reaction of this acetylenic p-nitrophenyl ester on reaction with cyclodextrin under our conditions is 100,000-fold, close to that for the... 

Novel materials were prepared by electrochemical copolymerization of thiophene with thiophene-3-acetic acid (XV) [49], The incorporation of the —COOH group allows for the loading of metal catalysts into these systems. These copolymers were soluble and had high degrees of polymerization (>2000). Copolymers between 3-methylthiophene and ferrocene esters of 2-(3-thienyl-ethanol) with varying alkyl chain lengths have been prepared (XVI) [50]. 

In view of the problem of polyalkylation which arises in these direct alkylation reactions, monoalkylated ferrocenes are best prepared by indirect routes. Suitable methods include the reduction of ferrocene esters and acyls with lithium aluminium hydride [316, 317, 318], e.g. 

Ferrocene carboxylic acid [1271-42-7] M 230.1, m 210°(dec), 225-230°(dec). Yellow crystals from pet ether. Also crystd from aqueous ethanol. [Matsue et al. J Am Chem Soc 107 3411 1985.] Acid chloride m 49° crystallises from pentane, Xmax 458nm [J Org Chem 24 280 1959], Methyl ester crystallises from aq MeOH m 70-71°. Anhydride m 143-145° from pet ether [J Org Chem 24 1487 7959]. Amide m 168-170° from CHCl3-Et20 or m 167-169° from C6H6-MeOH. [J Am Chem Soc 77 6295 1955 76 4025 7954.]... 

Ferrocene-1,1 -dicarhoxylic acid [1293-87-4] M 274.1, m >250°(dec), >300°. Orange-yellow crystals from AcOH. Sublimes above 230°. Monomethyl ester m 147-149° [Dokl Acad Nauk USSSR 115, 518 1957]. Dimethyl ester m 114-115° [J Am Chem Soc 14, 3458 1958]. Diacid chloride m 92-93° from pet ether. [Dokl Acad Nauk SSSR 120 1267 1958 127 333 7959.]... 

Borate esters react with the lithium compound to yield (r/ -cp)Fe(r 5-cp-B(OR)2), which can be hydrolyzed to produce (//5-cp)Fe(r/5-cp-B(OH)2). This compound will undergo many reactions that lead to additional ferrocene derivatives. For example, the reaction with CH3ONH2 produces the aminoferro-cene. The boric acid derivative will react with AgO in a coupling reaction that produces the "diferrocene" shown as... 

Further developments of ferrocene based esters led to even faster acyl transfers to /3-CD (Trainor and Breslow, 1981 Breslow et al., 1983), the most spectacular rate accelerations, up to 6 million, being with the derivatives [17] and [18] in which an acrylate moiety is conformationally... 

Czamieki and Breslow (22) have studied the rate of acyl transfer from a substrate that is bound by the acyl part rather than by the leaving group. Having shown that ferrocene binds strongly to -cyclodextrin, Czamiecki and Breslow employed the p-nitrophenyl ester of ferrocinnamic acid in kinetic studies using DMSO-buffer mixtures. A rate acceleration of 51,000 times background was observed for acylation of /i-cyclodextrin. 

Togni and Spindler introduced non-C2-symmetric ferrocene-based Josiphos-type ligands [47], which are effective for rhodium-catalyzed hydrogenation of a-(acetami-do)cinnamate, dimethyl itaconate, and / -keto esters. The Josiphos-type hgands have been applied as the stereodefming step in a number of industrial processes, as exemplified the use of PPF- Bu2 for the commercial synthesis of (-i-)-biotin [48], and Xyli-Phos for the preparation of the herbicide (S)-metolachlor [49]. 

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