Organolithiums as Useful Synthetic Intermediates for Tandem Reactions

Abstract

Introduction Functionalized Chains Carbocyclic Compounds Heterocycles Conclusions Acknowledgments

Intramolecular carbolithiation‐cyclization‐electrophilic substitution: solvent effect and mechanistic study

“…Most of the reported literature with organolithium reagents focuses the attention on the solvent effect on the aggregation state of the lithiating agent, but only a few examine how this effect changes the product distribution . The nature of the solvent could affect the stability of some of the intermediates and also the dynamic equilibrium, favoring the formation of new products and/or increasing the yield of formerly minor products.…”

“…Tandem sequences involving halogen/lithium exchange and intramolecular carbolithiation-cyclization-electrophilic substitution provide fascinating approaches to challenge synthetic issues. [1,2] The carbolithiation reaction attracts the interest of synthetic organic chemists, as it offers a convenient pathway for the efficient building of new carbon-carbon bonds by addition of an organolithium reagent to nonactivated alkenes or alkynes, and the possibility of introducing further functionalization on the molecule by trapping the reactive organolithium intermediate with electrophiles. [3] The subtle control of chemoselectivity, regioselectivity, and stereoselectivity achievable within carbolithiation points the way toward exciting applications in carbocyclic, heterocyclic, alkene, and alkane synthesis.…”

“…d)-phenyl (E)-3-phenyl-2-propenyl ether (2) Solid, mp 67.5-68.5°C 1. H NMR (200 MHz, CDCl 3 ) δ data: 4.70 (dd, 2H, J = 5.7 and 1.3 Hz), 6.42 (dt, 1H, J = 15.8 and 5.7 Hz), 6.74 (d, 1H, J = 15.8 Hz), 6.94-6.98 (m, 2H), 7.23-7.43 (m, 7H).…”