Copper catalysis allylic substitution

The method was later extended to the synthesis of a number of meroter-penoids from epoxygeranyl carbonates or acetates in a two-step approach combining titanocene catalysis with Stifle reactions (carbonates) [108,109] or copper-catalyzed allylic substitutions (acetates) [110-112], The cyclizations... 

Allyl methyl ether (ethyl diazoacetate, rhodium catalysis) and allyl terf-butyl ether (dimethyl diazomalonate, copper catalysis) yield cyclopropanes exclusively. With y-substituted allyl methyl ethers, C-0 insertion is generally strongly favored over cyclopropanation, even with tetraacetatodirhodium as catalyst.In view of these findings, the cyclopropanation of ( )- ,4-dibenzyloxybut-2-ene in moderate yield, only, to give (la,2a,3j5)-31 is notable. 

Trisox as a Bidentate Ligand Chiral Trisoxazolines in Copper(ll) Lewis Acid Catalysis and Palladium-Catalyzed Asymmetric Allylic Substitutions... 

Scheme 3.9 Tandem Michael-allylic substitution reaction catalysed by a combination of chiral copper catalysis and palladium catalysis.

Recently, Hiersemann reported the first catalytic enantioselective Claisen rearrangement (Scheme 2.4) [11]. The 2-alkoxycarbonyl-substituted allyl vinyl ethers 11 are reactive under the Lewis acid catalysis. Therefore, the Claisen rearrangements proceed catalytically [12]. Usually the Lewis-acid-catalyzed Claisen rearrangement does not proceed catalytically because of a higher affinity of the carbonyl product for the Lewis acids than the ether substrate. But this 2-alkoxycarbo-nyl-substituted substrate 11 can coordinate to metals in a bidentate fashion. This 2-alkoxycarbonyl substrate has higher affinity for Lewis acidic Cu complexes than the simple ether substrate. In this system, chiral copper (II) bisoxazoline Cu (box) complex 13 is effective for the enantioselective Claisen rearrangement. 

In 2013, Riant et al. developed a novel enantioselective domino conjugate reduction-allylic allylation reaction based on a cooperative dual catalysis involving a chiral copper catalyst and an achiral palladium catalyst. The reaction occurred between cyclic a-substituted a,(3-unsaturated ketones and ally methylcarbonate, providing the corresponding chiral cyclic a-allylic... 

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