Beilstein J. Org. Chem.2024,20, 1405–1411, doi:10.3762/bjoc.20.122
; lithium salt activation; olefinoxyamination; oxazoline; Introduction
Hypervalent iodine(III) reagents, also known as λ3–iodanes, have been well established and used in organic synthesis for the past decades [1][2][3][4][5]. The pioneering works of Fuchigami and Fugita, Ochiai, Kita, and later the
hypervalent iodine catalyst. The cationic hypervalent iodine catalyst could then activate the olefin to allow the addition of bifunctional nucleophiles such as an amide to achieve an overall olefinoxyamination process. We have previously reported a series of iodide-catalyzed processes, in which the
alkenes regioselectively to furnish their respective oxazoline regioisomer (Scheme 1d). Herein, we report that lithium salts such as LiBF4 or LiPF6, which are often used in lithium-ion batteries, can be used to activate hypervalent iodine catalysts to enable olefinoxyamination reactions with simple
Beilstein J. Org. Chem.2016,12, 22–28, doi:10.3762/bjoc.12.4
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Keywords: copper; electrophilic amination; olefinoxyamination; Introduction
The 1,2-oxyamino motif is highly valuable and found in a vast range of biologically active natural products, pharmaceuticals, and agrochemicals (Figure 1) [1][2]. Representative examples include salmeterol (Advair®), a β2
class of molecules is highly valued. Toward this end, intermolecular olefinoxyamination allows for direct and modular installation of both oxygen and amino groups to readily available olefins in a single step, representing a powerful and appealing approach over multistep sequences [7][8][9]. Sharpless
reported the first examples of this strategy using osmium tetroxide and amines to generate imido osmium intermediates (Scheme 1A) [10][11][12]. Although this transformation has received extensive application, the development of less toxic olefinoxyamination methods is greatly desired. In 2006, Stahl and
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Graphical Abstract
Figure 1:
Examples of valuable 1,2-oxyamino-containing molecules.