Copper‐Catalyzed Asymmetric Silylation of Propargyl Dichlorides: Access to Enantioenriched Functionalized Allenylsilanes

Abstract

A copper‐catalyzed silylation of propargyl dichlorides was developed to access chloro‐substituted allenylsilanes under mild reaction conditions. Moreover, enantioenriched chloro‐substituted allenylsilanes can be synthesized in moderate to high yields and good enantioselectivities with this protocol.

Protein‐Mediated Suppression of Rolling Circle Amplification for Biosensing with an Aptamer‐Containing DNA Primer

“…In this case, RCA was inhibited due to the inability of ϕ29DP to read through the bound protein and extend the primer. However, this approach requires that linear aptamers be ligated to form circular aptamers, which can severely alter performance, or that circular aptamers be selected directly from circularized pools of DNA . Given that the vast majority of aptamers are linear, we were interested in determining whether a protein‐aptamer complex that was partially complementary to a circular template (i.e., an aptaprimer) would prevent RCA owing to an inability to bind the circular template, as such an approach should be amenable to any linear aptamer and thus be more versatile.…”

Activation of the Si–B interelement bond related to catalysis

“…In 2019, Xu and Loh accomplished an enantioselective propargylic silylation of propargylic dichlorides by copper catalysis with Box ligand L37 (Scheme 102). 122 Propargylic substitution occurred in the presence of CuF 2 /L37/TMP/MeOH to yield a series of enantioenriched chloro-substituted allenylsilanes. The reaction is general for various aryl-substituted propargyl dichlorides, providing chiral allenylsilanes in moderate to high yields and with good ee values (322a-e -323a-e, Scheme 102, top).…”

Enantioconvergent and Regioselective Synthesis of Allenylsilanes by Nickel-Catalyzed C(sp2)–C(sp3) Cross-Coupling Starting from Racemic α-Silylated Propargylic Bromides

“…The silyl group will secure high γ-selectivity, thereby providing the direct preparation of enantioenriched allenylsilanes from racemic precursors . Examples for this are still rare, as the vast majority of their syntheses relies on enantioselective or -specific S N ′ displacements of propargylic acceptors with or without a silyl substituent at the alkyne terminus when carbon or silicon nucleophiles are employed, respectively.…”