Asymmetric nitroalkylation

Unlike nitroalkylation reactions, employing allylic ethers as reagents in C-glycoside chemistry has proven to be substantially more useful. These reactions, illustrated in Figure 7.13, show a propensity for a selectivity and are able to provide additional asymmetric centers. However, these... 

Michael addition of arylnitroalkenes to indole affords 3-(P-nitroalkyl)indoles 23 [143] in the presence of the Zn(OTf)2-complex with a chiral bisoxazoline ligand high stereoselectivities are observed [144], Likewise, benzylidene malonates undergo highly selective asymmetric Michael addition to the 3-position of indole ( 25) in the presence of a Cu(OTf)2-complex with a chiral bisoxazoline [145], To the group of Michael addition-related indole reactions (formally) belong the FeCls-catalyzed addition of acety-lacetone [146] and the Sc(OTf) 3-catalyzed addition of the acylaUene 26 [147] to afford 3-substituted indole derivatives 27. 

The Trauner retrosynthesis of amathaspiramide F commenced with a disconnection of the A(-acyl hemiaminal group to amino aldehyde 9, which could be derived from a Nef reaction of nitroalkyl 10 (Scheme 2). It was envisioned that Seebach s asymmetric alkylation of ot-amino acids could be utilized in the conjugated addition of A(,A(-acetal ent-2 with nitrostyrene 3. Trauner initially surmised that o-proline was required as the starting material, since previous work by Seebach had shown that alkylation occurs on the same face as the f-butyl group. 

Michael addition 253 a-nitroalkenes 638 nitroalkylation 1180 -asymmetric 1180 nitroalkyls 841... 

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