Three-Membered Aluminacycles

Abstract

Three-membered-ring scaffolds of carbocycles, namely, cyclopropanes and cyclopropenes, are ubiquitous in natural products and pharmaceutical molecules. These molecules exhibit a peculiar reactivity, and their applications as synthetic intermediates and versatile building blocks in organic synthesis have been extensively studied over the past century. The incorporation of heteroatoms into three-membered cyclic structures has attracted significant attention, reflecting fundamental differences in their electronic/geometric structures and reactivities compared to their carbon congeners and their associated potential for exploitation in applications. Recently, the chemistry of low-valent aluminum species, alumylenes, dialumenes, and aluminyl anions, has dramatically developed, which has allowed access to hitherto unprecedented aluminacycles. This Perspective focuses upon advances in the chemistry of three-membered aluminacycles, including their synthetic protocols, spectroscopic and structural properties, and reactivity toward various substrates and small molecules.

3-Fluoro-2H-azirine: Generation, Characterization, and Photochemistry

“…Three-membered organic heterocycles are versatile building blocks that have attracted considerable interest in synthetic and biological chemistry. − 2 H -Azirine, the simplest unsaturated heterocycle consisting of a nitrogen atom, has been the target of numerous experimental and theoretical studies since its first synthesis in 1932 by Neber. − These intensive studies mostly originate from the high strain of the three-membered azirine ring in combination with sufficient stability for chemical modification, rendering 2 H -azirines widely applicable in the synthesis of functionalized amino compounds, heterocycles, and substituted allenes and aziridines. − In addition to their use as versatile synthetic blocks, 2 H -azirines are recognized as biologically active compounds. Recently, a novel reactive 2 H -azirine-based probe has been designed and utilized in the chemoselective modification of carboxyl groups in proteins under both in vitro and in situ conditions with excellent efficiency. , Medicinally, the azirine unit can also be found in natural antibiotics including ( R )-(−)- and ( S )-(+)-dysidazirine. , …”

Crystalline Neutral Aluminum Selenide/Telluride: Isoelectronic Aluminum Analogues of Carbonyls

“…After reacting 2 with an equivalent amount of 1-adamantylazide (AdN 3 ) in toluene at room temperature, we were able to rapidly produce orange solid 6 ( 77 Se NMR: 237.1 ppm) within 5 min (91% yield). X-ray diffraction confirmed that 6 is the first example of an Al- and Se-containing analog of aziridine, likely formed through a [3 + 2] cycloaddition of AdN 3 with 2 followed by N 2 elimination. It is noteworthy that the discovery of a three-membered AlSeN ring in 6 and four-membered AlTeNC and AlTeCC rings in 4 and 5 introduces previously unknown fragments.…”