Rhodium/Chiral Diene Complexes in the Catalytic Asymmetric Arylation of β‑Pyrazol-1-yl Acrylates

The asymmetric conjugate addition of arylboronic acids to substituted and unsubstituted β-pyrazol-1-yl (<i>E</i>)-<i>tert</i>-butyl acrylates <b>4</b> catalyzed by 5 mol % of the Rh­(I)/diene <b>2a</b> catalyst provided the corresponding addition products in 44–98% yield and 91–>99.5% ee. The method was applied to the formal synthesis of (3<i>S</i>)-3-aryl-3-(pyrazol-1-yl)­propanoic acid <b>1b</b> with agonistic activity toward the human GPR40 G-protein coupled receptor

Rhodium-Catalyzed Asymmetric Addition of Arylboronic Acids to β‑Nitroolefins: Formal Synthesis of (<i>S</i>)‑SKF 38393

An efficient enantioselective addition of an array of arylboronic acids to various β-nitrostyrenes catalyzed by a novel and reactive rhodium–diene catalyst (S/C up to 1000) was developed, providing β,β-diarylnitroethanes in good to high yields (62–99%) with excellent enantioselectivities (85–97% ee). The method was extended to 2-heteroarylnitroolefins and 2-alkylnitroolefins similarly providing the desired products with high enantioselectivities and yields. The usefulness of this method was demonstrated in the formal synthesis of the enantiomer of the dopamine receptor agonist and antagonist, SKF 38393

Enantioselective and Rapid Rh-Catalyzed Arylation of <i>N</i>‑Tosyl- and <i>N</i>‑Nosylaldimines in Methanol

Enantiomerically enriched tosyl-protected diarylmethylamines were rapidly prepared by the asymmetric addition of arylboronic acids to <i>N</i>-tosylaldimines under mild conditions in the presence of a catalyst prepared in situ from Rh­(I) and a chiral diene ligand. This methodology offers access to diarylmethylamines in good yields with excellent chiral purity at room temperature using MeOH as a solvent and NEt₃ as a base. Its synthetic utility was demonstrated by the preparation of (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline (<b>14</b>), an antagonist of the <i>N</i>-methyl-d-aspartate (NMDA) receptor

Enantioselective and Rapid Rh-Catalyzed Arylation of <i>N</i>‑Tosyl- and <i>N</i>‑Nosylaldimines in Methanol

Enantiomerically enriched tosyl-protected diarylmethylamines were rapidly prepared by the asymmetric addition of arylboronic acids to <i>N</i>-tosylaldimines under mild conditions in the presence of a catalyst prepared in situ from Rh­(I) and a chiral diene ligand. This methodology offers access to diarylmethylamines in good yields with excellent chiral purity at room temperature using MeOH as a solvent and NEt₃ as a base. Its synthetic utility was demonstrated by the preparation of (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline (<b>14</b>), an antagonist of the <i>N</i>-methyl-d-aspartate (NMDA) receptor