Organomanganese

The organomanganese chemistry of indole is primarily characterized by the activation of the pyrrolic counterpart. First of all, this is the coordination, which... 

The Ti coordination via the carbocycle prevails for indole and carbazole, although the species were also found in organomanganese and -iridium chemistry. Osmium carbonyls tend to produce the species with the bridging indole function. Some illustrations of the ti N) coordination exist. 

Table 12. Retentions and yields in organomanganese compounds (not including thermal treatment)...

Stoichiometric carbomanganation with well-defined organomanganese compounds 286... 

The stoichiometric carbometallation with well-defined organomanganese compounds has thus far been limited to those of organomanganesecarbonyl compounds. One of the apparently common characteristics among them is their strong tendency to exist as coordinatively saturated 18-electron species. As such, they must be rather inert toward alkynes and alkenes (cf. Scheme 3). Dissociation of one of the CO s or some other ligands would facilitate their... 

Organomanganese reagents can be used for the formation of ketones from acid chlorides with excellent functional group tolerance, the corresponding ketones isolated in good yield. Gallo et al. have reported some hetero-... 

Li et al.2S9 Nishikawa et al. described how an organomanganese compound could ring-open an allylic tetrahydropyran to give allylic secondary alcohols by a different mechanism.292... 

Selective addition to aldehydes. Organomanganese halides add to aldehydes selectively in the presence of ketones. This is true for RMnI, RMnBr, prepared from RLi and MnBr2, and for RMnCl, prepared from RLi or RMnX and MnCl2. ... 

Copper-Catalyzed Alkylation of Organomanganese Reagents Preparation of 2,2-Dimethyldecane from tert-Butyl Manganese Chloride. 

Organomanganese reagents have also been used to prepare numerous simple or functionalized ketones in high yields.10 They can be also used to carry out in high yields, at room temperature, various chemoselective 1,2-addition reactions, for example to keto aldehydes.11... 

COPPER-CATALYZED CONJUGATE ADDITION OF ORGANOMANGANESE CHLORIDES, RMnCI, to a,p-ETHYLENIC KETONES IN THF AT 0°C... 

The scope of the reaction has been successfully extended to a,p-ethylenic aldehydes,5 esters,6 and amides7 as well as to a,p-acetylenic ketones8 (see Table IV). With esters, the reaction must be performed in the presence of chlorotrimethylsilane (MeaSiCI) to avoid the Claisen reaction by trapping the intermediate enolate. In most cases the organomanganese procedure is simple and more efficient than the organocopper procedure. 

Good yields of 1,4-addition products have also been obtained with alkylidene malonate esters which generally react with organomanganese reagents in the absence of copper salts9 (see Table IV). 

In conclusion, copper-manganese-catalyzed organomagnesium reagents and copper-catalyzed organomanganese reagents are a simple, efficient, and economic alternative to copper-catalyzed organomagnesium reagents and especially to... 

Scheme 2.S7. Copper-catalyzed Michael addition reactions between organomanganese reagents and pulegone.

Alkylation of organomanganese reagents with alkyl bromides can also be improved by addition of CuCI (3 mol%). The reactions proceed at room temperature and are complete within a few hours [123, 130], The opening of epoxides is also improved under these conditions. The reaction also features good chemoselectivity, tolerating the presence of sensitive functions such as ketones (Scheme 2.59) [130]. 

Benzylic organomanganese reagents prepared by direct insertion of activated manganese metal display the same behavior (Scheme 2.60) [131]. Excellent results are also obtained for 1,4-additions of organomanganese reagents to unsaturated esters in the presence of CuCI (3 mol%) [127]. 

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