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Development of a practical asymmetric synthesis of a glucagon receptor antagonist drug candidate for the treatment of type 2 diabetes is described. The antagonist consists of a 1,1,2,2-tetrasubstituted ethane core substituted with a propyl and three aryl groups including a fluoro-indole. The key steps to construct the ethane core and the two stereogenic centers involved a ketone arylation, an asymmetric hydrogenation via dynamic kinetic resolution, and an anti-selective Friedel–Crafts alkylation of a fluoro-indole with a chiral α-phenyl benzyl cation. We also developed two new efficient syntheses of the fluoro-indole, including an unusual Larock-type indole synthesis and a Sugasawa-heteroannulation route. The described convergent synthesis was used to prepare drug substance in 52% overall yield and 99% ee on multikilogram scales.

A manufacturing route for the synthesis of raltegravir potassium 1 was developed via a thermal rearrangement of amidoxime DMAD adducts 6 to construct the key, highly functionalized hydroxypyrimidin...

The development of practical and efficient syntheses of the potent non-nucleoside reverse transcriptase inhibitors 1 and 2 is described. The preparation of 1 proceeded in four synthetic steps and in 48% overall yield from 3. The long-term synthesis of 2 proceeded in nine synthetic steps and in 47% overall yield from commercially available 2,6-diflurorpyridine. The route to 2 was highlighted by the three-step synthesis of intermediate 22 and the high yielding coupling between 18 and phenol 8. The overall sequence required no chromatography and has successfully been utilized for the manufacture of 2 on large scale.

Preparations are reported for an extensive series of phosphate salts of polyammonium species from the corresponding halide salts. The phosphate salts, as anhydrous materials, are liquid at or near room temperature. Three approaches for the preparation of these materials are noted, including treatment with aqueous hexafluorophosphoric acid, classical ion exchange methods, and treatment with 85% phosphoric acid. The last of these provides the most desirable results. Several monocationic phosphate salts have also been prepared for comparison with other types of ionic liquids.

The reactions of chiral benzyl carbocations bearing α-phenyl substituents with N-sulfonylated indoles afford 1,1,2-triarylalkanes with anti-selectivities. This outcome is a reversal of facial diastereoselectivity relative to Bach’s α-alkyl-bearing benzyl cations. The reactions are promoted by either a Bronsted acid (TFA) or Lewis acid (BF3·OEt2), offering differential diastereoselectivities and reactivities. The electronic properties of both reacting partners strongly influence the reaction rates and the product diastereoselectivities and appear to operate under kinetic control. This chemistry provides an efficient access to sterically congested tetrasubstituted ethanes.

The reactions of chiral benzyl carbocations bearing alpha-phenyl substituents with N-sulfonylated indoles afford 1,1,2-triarylalkanes with anti-selectivities. This outcome is a reversal of facial diastereoselectivity relative to Bach's alpha-alkyl-bearing benzyl cations. The reactions are promoted by either a Brønsted acid (TFA) or Lewis acid (BF3.OEt2), offering differential diastereoselectivities and reactivities. The electronic properties of both reacting partners strongly influence the reaction rates and the product diastereoselectivities and appear to operate under kinetic control. This chemistry provides an efficient access to sterically congested tetrasubstituted ethanes.

A new chiroptical spectroscopic approach, differential circularly polarized fluorescence excitation (CPE), can be used to provide a selective method for detecting the presence of zinc ions. The approach utilizes the same instrumentation as fluorescence-detected circular dichroism and provides strong contrast in metal detection due to response to both chelation-enhanced fluorescence and circular dichroism upon metal ion binding. The observed contrast is therefore better than either of the parent spectroscopic detection methods. CPE also provides a strategy to reduce interference from background such as protein-based tryptophan fluorescence.

A series of polyammonium halide salts have been converted to the phosphate ion form. The resultant salts constitute a new category of non-aqueous ionic liquid (NAIL); these new ionic liquids (Liquid Ionic Phosphates) have been characterized by standard methods and have been investigated for their electrical conducting characteristics.