Rhodium-Catalyzed Allylation Reactions

Abstract

Rhodium-catalyzed allylation reactions are well known for their unique selectivity and reactivity due to the high memory effect of Rh as compared to other metals. These reactions involve the substitution of allylic rhodium intermediates with a diverse range of different nucleophiles, leading to C–C and C–heteroatom bond formation. Modern organic chemists are, however, interested in atom-economical protocols under greener pathways and following recent increased understanding of mechanistic aspects of Rh-catalyzed allylation via the hydrofunctionalization of allenes or alkynes, great strides have made in the design and development of new atom-economical protocols. In this article, we review this field from its beginning to current state.1 Introduction2 Rhodium-Catalyzed Allylic Substitution3 Rhodium-Catalyzed Allylation with Allenes4 Rhodium-Catalyzed Allylation with Alkynes5 Rhodium-Catalyzed Allylation with Dienes6 Rhodium-Catalyzed Allylation by ARO of Oxabicyclic Alkenes7 Rhodium-Catalyzed Enantioselective Allylation in Natural Product and Drug Synthesis8 Conclusion

Enantioselective Addition of α‐Nitroesters to Alkynes

“…Using a combination of [Rh(cod)Cl] 2 , dppf, and diphenyl phosphate, we observe allylic α‐nitroketone, α‐nitroester, and α‐nitroamide products as single regioisomers (>20:1 rr ) with moderate to high diastereoselectivity (5:1–12:1 dr ) [17] . In accordance with previous reports, there is a preference for the branched regioisomer, which bears two contiguous stereocenters [10a–d, 12–14] . Our findings complement an enantioselective Pd‐catalyzed α‐nitroester allylation reported by Ooi and co‐workers [18] .…”

Applications of Transition‐Metal‐Catalyzed Asymmetric Allylic Substitution in Total Synthesis of Natural Products: An Update

“…Upon this conversion, up to two chiral centers can be generated, involving all-carbon quaternary ones. In 2007, Trost et al designed a new and concise protocol to synthesize (À )-terpestacin (16) by multiple usages of the α-diketone functionality, starting from the inexpensive and commercially available 2-hydroxy-3-methyl-2-cyclopenten-1-one (17). The first total synthesis [51] and the first enantiospecific synthesis of 16 [52] were described by Tatsuta et al in the late 1990s.…”

“…The first total synthesis [51] and the first enantiospecific synthesis of 16 [52] were described by Tatsuta et al in the late 1990s. The isolation of terpestacin (16), an attractive natural product, from fungal strain Arthrinium sp. FA1744 was reported by collaboration between Oka and Bristol-Myers Squibb in 1993.…”

“…Various metals including palladium, platinum, iridium, gold, molybdenum, rhodium, and ruthenium have been employed in AAS reaction, each has its own merits and drawbacks [11a,16] . A wide variety of research used a broad‐ranging of these metals on the soft stabilized nucleophiles for the AAS reaction [11b,13a,15c,17] .…”

Enantioselective Synthesis of 3-Allylindolizines via Sequential Rh-Catalyzed Asymmetric Allylation and Tschitschibabin Reaction

“…Transition-metal-catalyzed regio- and enantioselective allylic substitutions provide powerful methods to construct new carbon–carbon and carbon–heteroatom bonds . Our group recently developed a new catalyst based on Rh and chiral bisoxazolinephosphine ligands (NPN*) to realize the highly branch-selective allylic alkylation of a variety of weakly acidic nitrogen, oxygen, carbon, and sulfur pronucleophiles . The carbonate or the alkoxide anion generated during the formation of the π-allyl rhodium intermediate could be used as the mild base to activate the neutral pronucleophiles.…”