Here we describe general flow processes for the synthesis of alkyl and aryl azides, and the development of a new monolithic triphenylphosphine reagent, which provides a convenient format for the use of this versatile reagent in flow. The utility of these new tools was demonstrated by their application to a flow Staudinger aza-Wittig reaction sequence. Finally, a multistep aza-Wittig, reduction ...

It is shown that the N-(p-ethoxyphenyl) group on beta-lactams can be oxidatively removed by ceric ammonium nitrate in good yield. Fourteen new N-(p-ethoxyphenyl)-2-azetidinones 8a-n were synthesized through standard [2+2] ketene-imine cycloadditions (Staudinger reaction). Treatment of these compounds with ceric ammonium nitrate yielded the N-dearylated 2-azetidinones 9a-n in good to excellent y...

This study describes the symmetric synthesis of novel β-lactams derived from chrysene directed towards their SAR, as well as their biological activities against several cancer cell lines in vitro. To our knowledge, this is the first report on the synthesis and biological evaluation of optically active anticancer β-lactams. That these anticancer effects are not uniform against all tumor lines su...

In this review, we highlight groundbreaking discoveries and applications of Staudinger reactions in the molecular life sciences, starting from engineering ligation as a bioorthogonal reaction until most recent modern bioconjugation methods to generate next-generation biopharmaceuticals. Bioorthogonal refer set chemoselective transformations biological environments able take place presence natur...

Here, we present a simple, modular and efficient strategy that allows the 3'-terminal labeling of DNA, regardless of whether it has been chemically or enzymatically synthesized or isolated from natural sources. We first incorporate a range of modified nucleotides at the 3'-terminus, using terminal deoxynucleotidyl transferase. In the second step, we convert the incorporated nucleotides, using e...

The traceless Staudinger ligation can be mediated by phosphinothiols under physiological conditions. Proximal positive charges are necessary to achieve that transformation, presumably because those charges discourage protonation of the key iminophosphorane intermediate. Here, a series of cationic phosphinothiols is used to probe Coulombic effects on the traceless Staudinger ligation in aqueous ...

Capitalizing on a recently reported iminosugar-based aza-crown (ISAC) accessed by double Staudinger azaWittig coupling reaction, we have expanded the structural diversity of this new family sweet cyclam analogs. Replacement two secondary amines linking iminosugar units amide bonds obtained cyclodimerization with BOP and DIPEA led to macrocycle that did not demonstrate efficient Zn2+ chelation u...