The Merger of Isocyanide‐Based Multicomponent Reaction and Ring‐Closing Metathesis (IMCR/RCM)

Abstract

Isocyanide‐based multicomponent reaction (IMCR) is an excellent synthetic tool for the synthesis of versatile and complex organic molecules in a one‐pot manner. Their extraordinary ability in generating intermediate adducts bearing bi‐ or multi‐functional groups helps in the construction of even more complex products via their combination with various post‐transformation processes. Another efficient tool in modern organic synthesis is the ruthenium‐catalyzed ring‐closing olefin metathesis (RCM). Merging both expedient reactions would give us an extremely powerful approach towards the facile synthesis of complex cyclic olefins which are otherwise difficult to access. Despite their vast utility in various fields of organic chemistry, there is not a single exclusively devoted review on the potential synthetic utility of the IMCR/RCM merger. Thus, in this review, we have discussed the numerous useful IMCR/RCM combination strategies for the synthesis of cyclic olefins from the literature from 1999 until 2019. This review is organized according to the ring size formed during the process.

Enantiopure β-isocyano-boronic esters: synthesis and exploitation in isocyanide-based multicomponent reactions

“…1 H NMR, 13 C NMR and 11 B NMR spectra were recorded using a Bruker AV 400 Ultrashield spectrometer. 1 H NMR and 13 C NMR chemical shifts were reported in parts per million (ppm) downfield from tetramethylsilane, 11 B NMR chemical shifts were determined relative to BF 3 •Et 2 O and spectra were recorded using quartz NMR tubes. Coupling constants (J) were reported in Hertz (Hz).…”

“…Among IMCRs, long standing Ugi four-component reaction (U-4CR) leads to diversely substituted peptidomimetic backbones starting from abundantly available building blocks and, in combination with subsequent cyclization reactions, has become a valuable tool in the design and synthesis of cyclic constrained peptidomimetics and heterocyclic compounds [ 8 , 9 ], also contributing in recent years to the emergence of many important drugs for the treatment of several diseases [ 10 ]. By tactical application of multi-functionalized building blocks and combination with other prominent synthetic strategies, such as ring closing metathesis [ 11 ] or Pd-catalyzed reactions [ 12 ], high molecular diversity can be rapidly achieved by IMCRs [ 13 ], establishing their relevance also in the total synthesis of complex natural products [ 14 ]. Finally, IMCRs offer multiple possibilities for polymer chemistry, as demonstrated with the synthesis of monomers and grafting-onto reactions, as well as direct polymerizations [ 15 ].…”