Manganese derivatives

King, R.B. and Diefenbach, S.P., Transition-metal cyanocarbon derivatives. 5. Reactions of (l-chloro-2,2-dicyanovinyl)manganese derivatives with trialkyl phosphites. A novel variant of the Michaelis-Arbuzov reaction leading to [2,2-dicyanovinylphosphonato]metal complexes, Inorg. Chem., 18, 63, 1979. 

The manganese derivative 84, generated from the reaction of the uranium-carbene complex [UCp3(=C(H)PMe2Ph ] with [MnCp(CO)3], via initial... 

Supported iron porphyrins are less reactive than the corresponding manganese derivatives in the PhIO epoxidation of cyclooctene. 80% of olefin conversion was reached with MnBrgTMPS-PVP in 2 h, whereas only 10% was obtained with FeBrgTMPS-PVP in 6 h. 

Finally, we note a report of the synthesis and structure of a mixed transition metal-indium complex containing iron and manganese derived from the reaction between [Hg Mn(CO)5 2], [Fe(CO)5], and indium metal, viz. [ Fe(CO)4 2 /i-InMn(CO)5 2], 16 (27) (see Fig. 5). This complex is structurally similar to the manganese-indium complex 11 with each Mn(CO)4 fragment replaced in 16 by an Fe(CO)4 moiety. The increase in the electron count by two has been assumed to account for the absence of a Fe—Fe bond in 16 in contrast to the suggested presence of a corresponding Mn—Mn... 

Similar results have been obtained from porphyrin complexes of other metals.315 Few attempts appear to have been made to catalyze 02 production from these higher oxidation state manganese derivatives and this would appear to be an area warranting further study. 

The normal reaction of tertiary phosphines is to replace metal-coordinated carbonyl groups (Section III,E,1) or, less commonly, to form adducts with P—>Si bonds (Section III,D). In special cases, however, cleavage of the Si-metal bond may occur directly (entries 63, 66, 66a, and 67) the manganese derivative is discussed further in Section... 

In contrast to the behavior of the manganese derivative (LXVIII), the iron compound undergoes carbonyl substitution without cleavage of the Si-M bond (entry 7). 

Structural features of the compounds in entries 1-6 have already been discussed in Section IV,A. The manganese compound in entry 2 (and its rhenium analog) were prepared by heating Ph2SiH2 with the metal carbonyl M2(CO)i0 similar germanium- and tin-manganese derivatives have been made via Eq. (144) (263, 414). 

The resulting solution will contain saline impurities such as salts of iron and manganese derived from the barium peroxide. These can be removed by the addition of a little phosphoric acid followed by neutralisation with barium hydroxide solution when the metals are precipitated as phosphates. If necessary, further addition of barium hydroxide may be made m order to precipitate the hydrogen peroxide as pure barium peroxide, which on treatment with the correct quantity of dilute sulphuric acid will give a pure solution of hydrogen peroxide. 

A similar procedure yielded the manganese derivatives from 3-bromothiophene and 3,4-dibromothiophene <1997TL993, 1997JOC6921>. Starting from 3,4-dibromothiophene, unsymmetrically substituted thiophenes could be prepared through a stepwise process. 

The manganese derivative Mn[CH3C(0)CHC(0)Fc]3 is oxidized at potential values 50 mV lower than that of the free ferrocenyl ligand. In addition, it exhibits the chemically reversible Mn(III) Mn(II) reduction at —0.36 V which, as expected, appears slightly more negative than that of Mn(acac)3 (Section IV.B.2.C.). 

Carbonyl insertions into rhenium-carbon bonds have been less studied than with manganese derivatives. Insertions of CO into rhenium-carbon bonds are more difficult than for manganese as expected from the higher BDE of the rhenium-hydrocarbyl bond with respect to the corresponding manganese-hydrocarbyl systems... 

The following rhenium cyclic compound does not undergo acyl formation with CO whereas ring expansion with CO occurs with the corresponding manganese derivative ... 

Ultrafast kinetic studies have been performed on the insertion of photolyti-cally generated singlet and triplet CpM(CO)2 (M = Re, Mn) intermediates into the Si-H bond of the (C2Hs)3SiH molecule. The rhenium compound is a singlet, whereas the manganese derivative is primarily a triplet under the experimental conditions, and this has been shown to affect the kinetics of the two processes (35). 

In 1983, Groves demonstrated the stoichiometric aziridination of alkenes from a manganese-imido complex generated in situ from an isolable (porphyrin)man-ganese-nitrido intermediate (Scheme 1) [4]. This reactivity has recently been exploited with success by DuBois, Carreira and coworkers in the context of (salen)manganese-derived systems for the amination of enol ether derivatives (Scheme 2) [5,6,7,8]. Although not isolated, aziridine intermediates are probably involved in these reactions. 

Epoxide products are formed in >95% selectivity with little to no aUylic oxidation side products, indicating that the involvement of radical species, such as HO and HOO, are unlikely (166, 201). The results for epoxidation reactivity of the manganese derivatives follow the same general trend observed... 

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