Stereoselective Synthesis of Functionalized 1,3-Disubstituted Isoindolines via Rh(III)-Catalyzed Tandem Oxidative Olefination-Cyclization of 4-Aryl-cyclic Sulfamidate-5-Carboxylates.

A new method for the direct, stereoselective synthesis of highly functionalized 1,3-disubstituted isoindolines 6 from enantiomerically enriched cyclic 4-aryl-sulfamidate-5-carboxylates (5) is described. The process involves sulfamidate directed, Rh(III)-catalyzed tandem ortho C-H olefination of the 4-aryl-sulfamidate-5-carboxylates and subsequent cyclization by aza-Michael addition. In the reaction, which generates trans-1,3-disubstituted isoindolines exclusively, the configurational integrity of the stereogenic center in the starting cyclic sulfamidate is completely retained in the product. Examples are provided which show that the cyclic sulfamidate moiety not only serves as a chiral directing group but also as a versatile handle for further functionalization of the generated isoindoline ring system.

Stereoselective synthesis of 1,3-disubstituted isoindolines via Rh(III)-catalyzed tandem oxidative olefination-cyclization of 4-aryl cyclic sulfamidates.

Rh(III)-catalyzed tandem ortho C-H olefination of cyclic 4-aryl sulfamidates (1) and subsequent intramolecular cyclization are described. This reaction serves as a method for the direct and stereoselective synthesis of 1,3-disubstituted isoindolines (3) starting with enantiomerically enriched 4-aryl cyclic sulfamidates. In this process, the configurational integrity of the stereogenic center in the starting cyclic sulfamidate is completely retained. In addition, the process generates trans-1,3-disubstituted isoindolines exclusively.

Dynamic kinetic resolution based asymmetric transfer hydrogenation of α-alkoxy-ß-ketophosphonates. Diastereo- and enantioselective synthesis of monoprotected 1,2-dihydroxyphosphonates.

Dynamic kinetic resolution driven, asymmetric transfer hydrogenation reactions of a wide range of 2-substituted α-alkoxy-ß-ketophosphonates 3 were observed to proceed efficiently to give the corresponding 2-substituted α-alkoxy-ß-hydroxy phosphonates 4 with excellent levels of diastereo- and enantioselectivity. These processes are promoted by using well-defined, commercially available, chiral transition metal catalysts and a 0.2:1 mixture of formic acid and triethylamine as the hydrogen source and solvent.

Dynamic kinetic resolution-based asymmetric transfer hydrogenation of 2-benzoylmorpholinones and its use in concise stereoselective synthesis of all four stereoisomers of the antidepressant reboxetine.

Dynamic kinetic resolution-driven, asymmetric transfer hydrogenation reaction of 2-benzoylmorpholin-3-ones (4) proceeds efficiently to give the corresponding (2R,3S)- or (2S,3R)-2-(hydroxyphenylmethyl)morpholin-3-ones (6) with an excellent level of diastereo- and enantioselectivity and simultaneous control of two contiguous stereogenic centers in a single step. This process is employed to prepare all four stereoisomers of the antidepressant reboxetine.