A Catalytic Enantiotopic-Group-Selective Suzuki Reaction for the Construction of Chiral Organoboronates

Abstract

Catalytic enantiotopic-group-selective cross-couplings of achiral geminal bis(pinacolboronates) provide a route for the construction of nonracemic chiral organoboronates. In the presence of a chiral monodentate taddol-derived phosphoramidite ligand, these reactions occur with high levels of asymmetric induction. Mechanistic experiments with chiral 10B-enriched geminal bis(boronates) suggest that the reaction occurs by a stereochemistry-determining transmetalation that occurs with inversion of configuration at carbon.

Enantioselective 1,1-Arylborylation of Alkenes: Merging Chiral Anion Phase Transfer with Pd Catalysis

“…In a related contribution, Morken and co-workers have disclosed an enantioselective Suzuki reaction of 1,1-diboronates to provide highly enriched boronic esters (Figure 1c). 10 While these methods ultimately access valuable enantioenriched benzylic boronates, they require a multistep synthetic sequence. From the perspective of synthetic divergence and step-economy, an ideal transformation would involve one-step installation of both the boronate and aryl functional groups (Figure 1d).…”

At the Forefront of the Suzuki–Miyaura Reaction: Advances in Stereoselective Cross-Couplings

“…In 2014, the Morken group reported the successful cross-coupling of prochiral 1,1-diboryl compounds of type 66 to give optically enriched organoboronates by Scheme 16 Copper-catalysed synthesis of optically enriched 3,3-diboronyl carboxyesters Scheme 15 Retentive cross-coupling of α-benzyloxytrifluoroborates Scheme 17 Chemo-and stereoselective cross-coupling of 3,3-diboronyl carboxyesters using a chiral catalyst (Scheme 18) [82]. In this catalytic, enantioselective desymmetrization process, the optimal ligand was found to be TADDOL-derived phosphoramidite 67.…”

Pd(0)-Catalyzed Cross-Coupling of 1,1-Diboronates with 2,2′-Dibromobiphenyls: Synthesis of 9H-Fluorenes

“…Yield 45% (201 mg 8, 136.9, 135.0, 128.8, 126.0, 112.6, 83.0, 38.4, 27.9, 24.9, 24.5 Preparation of Bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)methane 4. 15 An oven-dried Schlenk flask was charged with CuI (0.19 g, 1 mmol), B 2 pin 2 (5.08 g, 20 mmol), PPh 3 (0.34 g, 1.3 mmol), and LiOMe (1.14 g, 30 mmol). After being degassed and filled with N 2 , CH 2 Br 2 (1.74 g, 10 mmol) dissolved in DMF (20 mL) was added.…”