[1.1.1]Propellane

Synthesis of BCP Benzylamines From 2‐Azaallyl Anions and [1.1.1]Propellane

“…Functionalized BCPs are primarily derived from additions to [1.1.1]propellane ( 1 ), a highly strained small molecule which is reactive across its central bond. Though hundreds of reactions of [1.1.1]propellane with a variety of reagents are known, the routes to synthetically useful BCPs are often lengthy and plagued with side products. Recent efforts from the synthetic community have greatly expanded access to BCP‐containing small molecules (Scheme a): Baran reported a direct amination of [1.1.1]propellane, solving the longstanding challenge of efficient bicyclo[1.1.1]pentan‐1‐amine synthesis; towards the synthesis of 3‐aryl BCP‐amines, Uchiyama developed a carboamination of [1.1.1]propellane, a rare example of a one pot, highly controlled 1,3‐difunctionalization; in an elaboration of early work on cross‐coupling of organometallic BCPs, Knochel disclosed an efficient method for the synthesis of 1,3‐diarylated BCPs .…”

One-Pot Synthesis of Strain-Release Reagents from Methyl Sulfones

“…In particular, “strain-release” (also known as “spring-loaded”) reagents, defined as highly strained (>50 kcal/mol) bi- or tricyclic molecules that react via cleavage of their bridging bond resulting in the release of strain, , have become increasingly prominent in recent years. Those include bicyclo[1.1.0]­butanes (BCB), , bicyclo[2.1.0]­pentanes (housanes), tricyclo­[1.1.1.0 1,3 ]­pentanes (TCP or propellanes), and 1-azabicyclo[1.1.0]­butanes (ABB), leading to the formation of functionalized cyclobutanes, cyclopentanes, bicyclo[1.1.1]­pentanes, and azetidines, respectively, following the strain-release process. Some of these moieties are also found directly in natural products or utilized in medicinal chemistry for the introduction of bioisosteres .…”