8,11-Dichloro-N-tosyl-3-aza[5]metacyclophane:  A Highly Strained Aromatic System

Syntheses ofgem-Dihalocyclopropanes and Their Use in Organic Synthesis

“…153 Ketone-derived enol esters add dichlorocarbene exclusively, often in high yields. 153,155 Selected ex- amples of gem-dichlorocyclopropanes formation from alkenes substituted by two (or more) different functional groups [156][157][158][159][160][161][162][163][164][165][166][167] are presented in Table 4.…”

Contractive Annulation: A Strategy for the Synthesis of Small, Strained Cyclophanes and Its Application in the Synthesis of [2](6,1)Naphthaleno[1]paracyclophane

“…It involves the conversion of a bridged, nonplanar “pre‐arene” ( 1 ) into the corresponding cyclophane 2 by some sort of aromatization reaction (Scheme ). Using this approach, only benzene and pyrene have been bent to the limits of stability, as exemplified by the cyclophanes 4 , 6 , 8 and 10 , which were generated from the bridged Dewar benzenes 3 and 5 , the propellane 7 , and the bridged [2.2]metacyclophane‐1,9‐diene 9 , respectively. All other strategies for the synthesis of cyclophanes, that is, those based on macrocyclization or ring contraction, fail when called upon to deliver highly strained systems.…”

p -Toluenesulfonylmethyl Isocyanide: a Versatile Synthon in Organic Chemistry

“…It was found that compound 339 had an unpredicted decrease in overall ring strain compared with the carbon analog 319 and this was reflected in its high thermal stability and very low chemical reactivity [101]. …”