Domin S, Plata P, Zambroń BK. Diastereoselectivity Switch in the Pd(0)/InI-Mediated Reactions of β-Lactams with Aldehydes: An Entry into Nonracemic Semiprotected (3
E)-2,6-Enediols.
J Org Chem 2019;
84:12268-12280. [PMID:
31490071 DOI:
10.1021/acs.joc.9b01471]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The switch from N-methylimidazole (N-MI) to the Et3N N-ligand efficiently alters diastereoselectivity in Pd(0)/InI-mediated allylations of aldehydes with β-lactam-derived organoindiums. As a result, (3E)-selective allylations and crotylations of a variety of aliphatic and (hetero)aromatic aldehydes with differently substituted chiral ε-amido-allylindiums were developed. Depending on the relative β-lactam configuration, the reactions occur under kinetic or thermodynamic control, with effective remote 1,5- or 1,4,5-asymmetric induction to afford a diversity of previously unavailable (3E)-2,5-syn-2,6-anti-, (3E)-2,5-anti-2,6-anti-, and (3E)-2,5-anti-2,6-syn-substituted enediols, amino alcohols, and homoallylic alcohols in modest to high yields and with moderate to excellent diastereoselectivity. The effect of the N-ligand as well as β-lactam and aldehyde structures on the yield and stereoselectivity was investigated.
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