Reciprocal polyhedra and the Euler relationship: cage hydrocarbons, CH and closo-boranes [BH]

Kinetic stabilization allows structural analysis of a benzoborirene

Formal reduction of (2-bromophenyl)chloro(2,2'',4,4'',6,6''-hexaisopropyl-[1,1':3',1''-terphenyl]-2'-yl)borane with tert-butyl lithium at low temperatures yields a highly strained benzoborirene that is kinetically stabilized by the bulky terphenyl substituent. The target compound withstands heating to 80 °C, and represents the first benzoborirene fully characterized by single-crystal X-ray crystallography. The bond length pattern of the six-membered ring of the parent benzoborirene follows an anti-Mills-Nixon distortion.

Design and synthesis of novel bis-annulated caged polycycles via ring-closing metathesis: pushpakenediol

Intricate caged molecular frameworks are assembled by an atom economical process via a Diels-Alder (DA) reaction, a Claisen rearrangement, a ring-closing metathesis (RCM) and an alkenyl Grignard addition. The introduction of olefinic moieties in the pentacycloundecane (PCUD) framework at appropriate positions followed by RCM led to the formation of novel heptacyclic cage systems.