Organic Methodology

A driving concern in our laboratory is the development of new synthetic methods for heterocyclic synthesis. One such reaction is the azide-Schmidt reaction, which is the acid-promoted combination of a carbonyl compound with an alkyl azide to form an amide. The original version we developed was the intramolecular Schmidt reaction, which was followed by variants including the “in situ tethering” Schmidt reaction of hydroxyalkyl azides and domino processes in which the rearrangement is combined with other Lewis acid-promoted transformations (such as Diels–Alder or Winstein rearrangements). We have also developed diastereotopic versions able to control stereochemistry and regiochemistry, which are useful for the synthesis of complex "libraries" of compounds suitable for screening.
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We are also oxaziridine enthusiasts, having studied the photochemical rearrangement of oxaziridines to lactams (shown here in a total synthesis of yohimbine) and Cu(I)-promoted SET reactions that can lead to products resulting from nitrogen radical cyclization or C–H functionalization, among others.
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While investigating the intramolecular Schmidt reaction, we used pi–cation and n–cation interactions in the context of controlling sterochemistry and regiochemistry. Although these interactions are common features in small molecule–protein interactions, they are rarely used in chemical synthesis. In addition, our group discovered a class of intriguing twisted amides in which the amide bond is somewhere between totally planar and totally orthogonal. These new agents have been used in a variety of reactions including mild and selective C–C activation reactions. The intramolecular Schmidt reaction has been applied to stereo- and regio- chemically controlled ring expansions in order to introduce a nitrogen-containing group in a complex molecular setting. The lab also continues to exploit the unique properties of fluorinated alcohols, such as hexafluoroisopropanol (HFIP), to promote unusual reactivity, as shown in recent rearrangements and Friedel-Crafts substitution chemistry. 

HFIP Friedel-Craft Chemistry

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