Highly Stereoselective Synthesis of Fluoroalkene Dipeptides via the Novel Chromium(II)-Mediated Carbon–Fluorine Bond Cleavage/New Carbon–Carbon Bond Formation

Abstract

An efficient chromium(II)-mediated reductive coupling reaction of various CBrF2-containing molecules and aldehydes has been developed. This reaction proceeds presumably via the monofluorinated dichromium(III) intermediate generated by the carbon?fluorine bond activation, and provides a general and straightforward access to synthesize a variety of (E)- or (Z)-?-fluoroallylic alcohols in a highly stereoselective manner. Based on the novel reductive coupling, four types of fluoroalkene dipeptide analogues could be stereoselectively prepared.

Development of Novel Solid-State Light-Emitting Materials Based on Pentafluorinated Tolane Fluorophores

“…Over the past few decades, we have focused on the development of efficient synthetic procedures toward versatile fluorine-containing molecules, , as we are interested in the unique ability of the fluorine atom to dramatically alter the chemical reactivity of compounds in addition to both their physical and chemical properties . On the basis of our accumulated knowledge into synthetic methodologies toward fluorinated organic molecules, we recently focused on the development of functional materials, that is, liquid-crystalline and photoluminescence (PL) materials, containing fluorinated partial structures.…”

Selective Synthesis of (Z)- and (E)-β-Fluoro-α,β-Unsaturated Amides Using Palladium-Catalyzed Aminocarbonylation

“…In 2016, the Konno group reported a chromium-mediated reductive coupling approach for the production of (E)-β-fluoro-α,β-unsaturated amides from β-difluorobromo amides and aldehydes (Scheme 1a). 14 Another report by the Colby group describes the use of morpholine 3,3,3-trifluoropropanamides and Grignard reagents to produce corresponding (E)-β-fluoro-α,β-unsaturated amides with moderate yields (Scheme 1b). 15 However, both methods have a limited scope with regard to the amide functionality.…”

“…Moreover, research on the synthesis of amides in the fluoro-α,β-unsaturated carbonyl family is scarce. In 2016, the Konno group reported a chromium-mediated reductive coupling approach for the production of ( E )-β-fluoro-α,β-unsaturated amides from β-difluorobromo amides and aldehydes (Scheme a) . Another report by the Colby group describes the use of morpholine 3,3,3-trifluoropropanamides and Grignard reagents to produce corresponding ( E )-β-fluoro-α,β-unsaturated amides with moderate yields (Scheme b) .…”