Allylchromium reagent

The advantages of allylchromium reagents in stereoselective synthesis were soon shown7 8- 9. Due to mild reaction conditions, sensitive functionalities - even epoxide rings10 -... 

Allylchromium reagents of similar reactivity may also be generated from allyl tosylates1, acrolein diethyl acetal13, and vinyloxiranes14. 

Oxygen-substituted allylchromium reagents are conveniently generated from vinyloxi-ranes by chromium(II) chloride in the presence of lithium iodide and aldehydes with high anti diastereoselectivity14. qh oh... 

Table 8 Enantioselective Addition of Allylchromium Reagents to Aldehydes (equation 61)...

Allylzinc and allylchromium reagents coordinated by chiral ligands have variable degrees of success in the preparation of optically active homoallylic alcohols. 

A-Protected amino aldehydes have been employed in the ehromium-mediated reaction of allylic halides [146]. A series of amino aldehydes bearing various N-protective groups are treated with allyl bromide and CrCl2 to produce the homo-ally lie alcohols 243 and 244 (Table 10-26). The reactions are very unselective with the simple allylchromium reagents unless a disubstituted amino group is employed. 

This paper will deal with four topics the first one is related to allylchromium reagents, while the latter three refer to the behavior of trialkylaluminum or related species in different situations. The authors main concern here is to describe new reactions useful for selective synthesis. 

Alcohol synthesis. Halogenated allylchromium reagents can be prepared and used in a reaction with carbonyl compounds. ... 

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