Lithium diallylcuprates

Lithium diallylcuprate, 11 Lithium dibutylcuprate, 61 Lithium dimethylcuprate, 63, 258 Sakurai reaction Alkylaluminum halides, 5 Allyltrimethylsilane, 11, 305 Titanium(IV) chloride, 304 with other organometallic agents (IS, 2S) -2-Amino-3-methoxy-1 -pheny 1-1-propanol, 17... 

Lithium dialkylcuprates-Boron trifluoride etherate, 208 Lithium diallylcuprate, 11 Lithium dibutylcuprate, 61, 208, 344 Lithium dibutylcuprate-Boron trifluoride etherate, 208 Lithium dimethylcuprate, 63, 151, 258 Lithium dimethylcuprate-Boron trifluoride etherate, 208 Organocopper reagents, 11, 61, 63, 131, 151, 207, 344 Organocopper reagents-Boron trifluoride etherate, 208 Organolithium reagents-Copper(I) halides, 58... 

In general, lithium diallylcuprates are not useful for conjugate Surprisingly, allylcoppers, prepared from allyltributyltins,... 

Conjugate addition to acyclic Michael acceptors. Sakurai and Hosomi (9, 445-446) reported one example of the fluoride ion-catalyzed reaction of allyltrimethylsilane with an acyclic enone. In that case (reaction with C6H5CH=CHCOCH,). 1.2- and 1,4-adducts are obtained in the ratio 2 1.1,4-Addition is enhanced by use of DMF and HMPT as solvent and by increase in the size of the group adjacent to the carbonyl group. 1,4-Addition is the main or predominant reaction with a,3-unsaturated esters or nitriles. In this case, it is superior to or competitive with allylation with lithium diallylcuprate. Yields in 1,4-additions to a,p-enones can compare favorably with those obtained with reactions catalyzed by TiC. ... 

Conjugate addition to 3-ethoxycarbonylcoumarin (117c) using lithium diallylcuprate affords the 1,4-adduct 124 in 83% yield while the application... 

The addition of lithium diallylcuprate to a, E-unsaturated carbonyl compounds is highly substrate dependent. Good yields can only be obtained with doubly activated esters as shown in (14) and (15). The importance of the conjugate addition has prompted numerous searches for procedures and methods to effect asymmetric induction. One recent example is the use of (S)-2-(methoxymethyl)pyrrol-idine as a chiral copper ligand (Scheme 48). ... 

Kharasch and Tawney (1941) reported that copper salts catalyze 1,4-addi-tion of Grignard reagents to a,jS-unsaturated ketones. Gilman et al. (1952) first discovered that phenylcopper reacts with benzalacetophenone in a 1,4-addition. Subsequently House and associates (1966) have revealed the scope of the conjugate addition of cuprate complexes. Now alkyl, vinyl, and aryl groups can be introduced specifically at the p position of a,jS-unsaturated carbonyl compounds. Transfer of an allyl group from lithium diallylcuprate to 2-cyclohexenone is also known (House and Fischer, 1969). However, ethynyl, cyano, and hetero groups attached to the copper atom are difficult to transfer to electron-poor olefins. 

A short and efficient synthesis of methyl jasmonate (91), an odoriferous metabolite of Jasminum grandiflorum, proceeds via simple vicinal bis-alkylation of cyclopent-2-enone by conjugate addition of lithium diallylcuprate, and alkylation of the resulting specific enolate with l-iodopent-2-yne (Scheme 22). A new synthesis of jasmone has been described, starling with the readily available levulinic acid. ... 

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