Synthetic Methods for Multiply Substituted Butadiene-Containing Building Blocks

Abstract

Conjugated organic systems have attracted much attention because new materials and functional structures can be expected from them. 2,4-Dienes mono-and disubstituted with electrophiles at the 1-and 1,6-positions, respectively, containing a butadienyl-conjugated skeleton and one or two terminal functional groups that can be manipulated, represent one of the most useful building units for the preparation of both cyclic and linear conjugated compounds. This account summarizes the synthetic methods available for multiply substituted butadiene-containing mono-or bis-electrophiles.

Isolation, Structural Characterization, and Synthetic Application of Oxycyclopentadienyl Dianions

“…This would not only contribute to the in‐depth understanding of reaction mechanisms but could also lead to the discovery of new synthetically useful reactions. In this context, we report here the first isolation and the X‐ray structure determination of a novel type of cyclic dianion, the fully substituted oxycyclopentadienyllithium compounds 2 , which were prepared by the reaction of the linear dianion 1 1e–g and CO (Scheme ) 4. Because of the concomitance of the CpLi moiety, the exocyclic oxy anion, and the multiple reactive sites, these OCp dianions 2 are structurally unique and display novel reaction chemistry towards organic substrates and organometallic compounds.…”

One-step synthesis of 1-halo-1,3-butadienes via ruthenium-catalysed hydrohalogenative dimerisation of alkynes

“…The most frequently used approach consists of halogenation of zircona-or titanacyclopentadienes. 4 However, these methods require the stoichiometric formation of an organometallic complex from two alkynes. Although the development of atom-economical single-step routes using a catalytic amount of metal is of special interest, few reports have been described.…”

Synthesis of Polysubstituted Cyclopentene and Cyclopenta[b]carbazole Analogues from Unsymmetrical 4-Arylidene-3,6-diarylhex-2-en-5-ynal and Indole Derivatives via an Iodine Mediated Electrocyclization Reaction

“…An electrocyclization strategy is one of the most powerful tools for constructing complex polycyclic carbocycles in a highly regioselective and atom-economic manner . The efficient use of dienal and ynal derivatives for preparing a large number of structurally diverse carbocyclic analogues via an electrocyclization approach would be of great interest to the synthetic community . Substituted cyclopentene scaffolds are components of a wide variety of natural products and exhibit a variety of pharmacological activities .…”