Allylations copper® chloride

When either an alcohol or an amine function is present in the alkene, the possibility for lactone or lactam formation exists. Cobalt or rhodium catalysts convert 2,2-dimethyl-3-buten-l-ol to 2,3,3-trimethyl- y-butyrolactone, with minor amounts of the 8-lactone being formed (equation 51).2 In this case, isomerization of the double bond is not possible. The reaction of allyl alcohols catalyzed by cobalt or rhodium is carried out under reaction conditions that are severe, so isomerization to propanal occurs rapidly. Running the reaction in acetonitrile provides a 60% yield of lactone, while a rhodium carbonyl catalyst in the presence of an amine gives butane-1,4-diol in 60-70% (equation 52).8 A mild method of converting allyl and homoallyl alcohols to lactones utilizes the palladium chloride/copper chloride catalyst system (Table 6).79,82 83... 

Attempts were made to extend the r,(7-transfer of allyl ligand from palladium to other, metals (fdf) (magnesium, copper, zinc, cadmium, and liquid gallium). It has been found that these metals do not form their respective allyl derivatives in reaction with rr-allyl-palladium chloride. 

In combination with the incremental advances concerning reaction conditions in recent years, especially for low-pressure carbonylations, there is a trend toward increasing use of this chemistry to synthesize advanced building blocks. In this respect carboxylation of alkenes with an appropriate alcohol or amine function leads to the formation of lactones or lactams. Thus, cobalt, rhodium, or palladium chloride/copper chloride catalysts convert allyl and homoallyl alcohols or amines to the corresponding butyrolactones or butyrolactams, respectively [15]. 

Note the particularly mild reaction conditions and the fact that the reaction depicted by Eq. (6) progresses without cleavage of the allylic hydroxyl group. These copper-modified nickel catalysts were found to be more selective than the analogous Cu(B) formulations derived from borohydride reduction of copper chloride [17]. Copper modification of Raney nickel has also been shown to benefit the selectivity of phenylacetylene hydrogenation, but not to the same extent as the Cu-Ni(B) catalyst. 

Flurochloridone is made by copper chloride-catalyzed cyclocondensation of N-allyl-(3-trifluormethylphenyl)dichloroacetamide 49 [34]. 

Allyl-substituted furans were synthesized efficiently in a direct procedure using 2-furanyUithium reagents and allyl bromides/chlorides, catalyzed by ligand-firee copper(I). The reactions took place under mild conditions,... 

An efficient copper-catalysed allylic trifluoromethylation reaction has been developed. This reaction provides a general and straightforward way to construct allylic trifluoromethylated compounds under mild conditions. The reaction employs cheap copper chloride as the catalyst and a hypervalent iodine(III) reagent as both the oxidant and the CF3 source. 

Cut LiCl with lithium naphthalenide, it is possible to prepare allylic copper species that undergo smooth addition to enones leading to the 1,4-addition product such as 8 in 92% yield [11], Remote ester-functionalized aryl- and alkyl-copper compounds can be readily prepared by this method [12], Remarkably stable ortho-halophenylcopper reagents obtained by the direct insertion of activated copper undergo substitution reactions with alkyl iodides, benzylic bromides and various acid chlorides [13,14]. 

Ttansmetalation of tliioetliets to organocopper compounds can also be performed in some special cases. Tluis, tteatment of the ester 119 with MeyCuLi-LiCN provides the copper reagent 120, which can be treated successfully witli several electrophiles such as allyl bromide ot acid chlorides to afford the expected products such as 121 iScbeme 2.54) [115, 116]. 

The allylation of aldehydes can be carried out using stannous chloride and catalytic cupric chloride or copper in aqueous media." In-situ probing provides indirect (NMR, CV) and direct (MS) evidence for the copper(I)-catalyzed formation of an allyltrihalostannane intermediate in very high concentration in water (Scheme 8.6). Hydrophilic palladium complex also efficiently catalyzes the allylation of carbonyl compounds with allyl chlorides or allyl alcohols with SnCl2 under aqueous-organic... 

The chloroacetoxylation reaction is synthetically useful since the chloride can be substituted with either retention [Pd(0)-catalyzed reaction] or inversion (Sjv2 reaction) by a number of nucleophiles. In this way both the cis and trans isomers are accessible and have been prepared from a number of allylic acetates (Schemes 5 and 6). In a subsequent reaction the allylic acetate can be substituted by employing a copper- or palladium-catalyzed reaction. The latter reactions are stereo specific. 

Nitroalkanes react with Jt-deficient alkenes, for example, p-nitro ketones are produced from a,P-unsaturated ketones [41], whereas allylic nitro compounds have been prepared via the Michael-type addition of nitroalkanes with electron-deficient alkynes (Table 6.19). The reaction in either dimethylsulphoxide [42] or dimethyl-formamide [43] is catalysed by potassium fluoride in the presence of benzyltriethyl-ammonium chloride the reaction with dimethyl acetylenedicarboxylate is only successful in dimethylsulphoxide [42], Primary nitroalkanes produce double Michael adducts [42,44], A-Protected a-aminoacetonitriles react with alkynes under catalysed solidiliquid conditions to produce the Michael adducts [45] which, upon treatment with aqueous copper(Il) sulphate, are converted into a,p-unsaturated ketones. 

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