Regioselective organocatalyzed asymmetric bromolactonization of aryl acrylate-type carboxylic acids: a new approach towards enantioenriched 3-substituted isobenzofuranones. Issue 19 (15th October 2016) - Gelat, Fabien
Graphical abstract: Abstract: The enantioselective synthesis of several 3-substituted isobenzofuranones has been developed through a new and flexible route. When combined with a catalytic amount of benzoic acid, quinidine thiocarbamate bifunctional catalysts have demonstrated their efficiency for the highly regioselective organocatalyzed asymmetric bromolactonization reaction of aryl acrylate-type carboxylic acids. Abstract : ( S ∗ )-Bromo-(( S ∗ )-3-oxo-1, 3-dihydroisobenzofuran-1-yl)acetic acid methyl ester: C11 H9 BrO4 Ee = 20% [ α ]D 20 = −11.8 ( c 1.5, CHCl3 ) Source of chirality: QDTC 4-OMe Relative configuration: ( S, S ) Abstract : ( S ∗ )-Bromo-(( S ∗ )-3-oxo-1, 3-dihydroisobenzofuran-1-yl)acetic acid ethyl ester: C12 H11 BrO4 Ee = 43% [ α ]D 20 = −19.6 ( c 1.5, CHCl3 ) Source of chirality: QDTC 4-OMe Relative configuration: ( S, S ) Abstract : ( S ∗ )-Iodo-(( S ∗ )-3-oxo-1, 3-dihydroisobenzofuran-1-yl)acetic acid ethyl ester: C12 H11 IO4 Ee = 27% [ α ]D 20 = −16.8 ( c 3.0, CHCl3 ) Source of chirality: QDTC 4-OMe Relative configuration: ( S, S ) Abstract : ( S ∗ )-Bromo-(( S ∗ )-3-oxo-1, 3-dihydroisobenzofuran-1-yl)acetic acid benzyl ester: C17 H13 BrO4 Ee = 44% [ α ]D 20 = −11.6 ( c 2.9, CHCl3 ) Source of chirality: QDTC 4-OMe Relative configuration: ( S, S ) Abstract : ( S ∗ )-Bromo-(( S ∗ )-3-oxo-1, 3-dihydroisobenzofuran-1-yl)acetic acid butyl ester: C14 H15 BrO4 Ee = 44% [ α ]D 20 = −14.7 ( c 2.5, CHCl3 ) Source of chirality: QDTC 4-OMe Relative configuration: ( S, S ) Abstract : ( S ∗ )-Bromo-(( S ∗ )-3-oxo-1, 3-dihydroisobenzofuran-1-yl)acetic acid phenyl ester: C16 H11 BrO4 Ee = 32% [ α ]D 20 = −9.6 ( c 1.0, CHCl3 ) Source of chirality QDTC 4-OMe: Relative configuration: ( S, S ) Abstract : ( S ∗ )-Bromo-(( S ∗ )-3-oxo-1, 3-dihydroisobenzofuran-1-yl)acetic acid tert -butyl ester: C14 H15 BrO4 Ee = 53% [ α ]D 20 = −15.4 ( c 1.0, CHCl3 ) Source of chirality: QDTC 4-OMe Relative configuration: ( S, S ) Abstract : ( S ∗ )-Bromo-(( S ∗ )-5-nitro-3-oxo-1, 3-dihydro-isobenzofuran-1-yl)acetic acid ethyl ester: C12 H10 BrNO6 Ee = 49% [ α ]D 20 = −2.6 ( c 1.0, CHCl3 ) Source of chirality: QDTC 4-OMe Relative configuration: ( S, S ) Abstract : ( S ∗ )-(( S ∗ )-5-Benzyloxy-3-oxo-1, 3-dihydro-isobenzofuran-1-yl)bromoacetic acid ethyl ester: C19 H17 BrO5 Ee = 10% [ α ]D 20 = −5.6 ( c 0.8, CHCl3 ) Source of chirality: QDTC 4-OMe Relative configuration: ( S, S ) Abstract : ( S ∗ )-Bromo-(( S ∗ )-5, 6-dimethoxy-3-oxo-1, 3-dihydro-isobenzofuran-1-yl)acetic acid methyl ester: C14 H15 BrO6 Ee = 22% [ α ]D 20 = −9.7 ( c 2.0, CHCl3 ) Source of chirality: QDTC 4-OMe Relative configuration: ( S, S ) Abstract : (( R )-3-Oxo-1, 3-dihydroisobenzofuran-1-yl)-acetic acid ethyl ester: C12 H12 O4 Ee = 38% [ α ]D 20 = +3.8 ( c 3.3, CHCl3 ) Source of chirality: QDTC 4-OMe Absolute configuration: (3 R )