The Application of Transition Metal Catalysis for Selective Cyclocarbonylation Reactions. Synthesis of Lactones and Lactams

Abstract

A variety of 5-, 6-, and 7-membered ring lactones and lactams have become available via carbonylative cyclization reactions catalyzed by different transition metal complexes. Palladium and rhodium complexes are the most widely used catalysts for the cyclization reactions. Furanones can be synthesized either by the catalytic intermolecular cyclocarbonylation of iodoarenes with alkynes or alkynols, or by intramolecular cyclocarbonylation of alkynols. g-Butyrolactones are mainly prepared by the intramolecular cyclocarbonylation of allyl alcohol derivatives catalyzed by palladium(0) complexes and 1,4-bis(diphenylphosphino)butane (dppb). The replacement of dppb by a chiral ligand leads to the formation of optically active γ-butyrolactones. Furthermore, 5-, 6-, and 7-membered ring bicyclic and polycyclic lactones and lactams are obtained by the Pd(II) catalyzed intramolecular cyclocarbonylation of 2-allylphenol and 2-allylaniline derivatives in the presence of syngas. The regiochemical control of the reaction depends on the choice of solvent, the nature of the metal and added ligand, and the relative pressures of the gases (CO and H 2 ). Lactones 2.3Synthesis of Five-, Six-, and Seven-Membered Ring bicyclic and polycyclic Lactones 3Catalytic Synthesis of Five-, Six-, and Seven-Membered Rings Lactams 4Conclusion

Pd‐Catalyzed Cyclocarbonylation of 2‐(2‐Bromoaryl)indoles with CO as a C1 Source: Selective Access to 6 H‐Isoindolo[2,1‐a]indol‐6‐ones and Indeno[1,2‐b]indol‐10(5 H)‐ones

“…166-167 8C; 1 HNMR (CDCl 3 ,4 00 MHz): d = 2.71 (s, 3H), 3.67 (s, 3H), 6.88-6.91 (m, 2H), 7.00-7.15 (m, 4H), 7.29 ppm (d, J = 7.2 Hz, 1H); 13 CNMR (CDCl 3 ,1 00 MHz): d = 20. 8, 31.5, 107.6, 115.3, 118.0, 122.8, 123.4, 123.8, 123.9, 129.3, 131.7, 134.5, 141.0, 142.8, 158.4, 184.3 ppm (one 13…”

“…On the other hand, the Pd-catalyzed cyclocarbonylation reaction with CO as aC 1s ource has emerged as ap owerful tool for the direct construction of various carbonyl-containing heterocyclic compounds in modern synthetic organic chemistry. [13] However, to the best of our knowledge,t he selective synthesis of 6 H-isoindolo[2,1-a]indol-6-ones and indeno [1,2-b]indol-10(5 H)-ones by employing aP d-catalyzed cyclocarbonylation reactionw ith CO as ac arbonyl source has not yet been reported. As ac ontinuation of our interesti nt he construction of indole-containing tetracyclic compounds, [14] herein we report ah ighly efficient Pd-catalyzed cyclocarbonylationr eactionof2 -(2-bromoaryl)indoles with CO (1 atm), therebyo ffering as traightforward and highly regioselective route to 6H-isoindolo[2,1-a]indol-6-ones and indeno [1,2-b]indol-10(5 H)-ones.…”

Solvent‐Switchable Regioselective Synthesis of Aurones and Flavones Using Palladium‐Supported Amine‐Functionalized Montmorillonite as a Heterogeneous Catalyst

“…[18][19][20][21] The transition-metal-catalyzed carbonylation reaction is an attractive method for the construction of various heterocyclic scaffolds as it utilizes CO gas as an inexpensive C 1 source. [22][23][24][25][26][27] In this regard, the Pd-catalyzed carbonylative cyclization of 2-iodophenolsw ith terminal alkynes is as ap rominentm ethod for the synthesis of flavones and aurones. Initially,C hiusoli and co-workersr eported the Pd-catalyzed protocol for the synthesis of aurones.…”

A General Cyclocarbonylation of Aryl Bromides and Triflates with Acetylenes: Palladium‐Catalyzed Synthesis of 3‐Alkylidenefuran‐2‐ones

“…Furanones represent an important family of organic compounds that are present in several natural products and bioactive derivatives. [1] More specifically, this structural motif is found in a wide variety of therapeutically interesting drug candidates that have anti-inflammatory, [2] cardiotonic, [3] analgesic, [4] anticancer, [5] anticonvulsant, [6] antimicrobial, [7] and antiviral activities [8] (Figure 1). Selected examples of currently marketed drugs with the furanone scaffold are Basidalin, Ascorbic acid, Narthogenin, Butalactin, and Rofecoxib.…”

“…Although several strategies are known for the preparation of a variety of furanone derivatives, [1] the synthesis of 3-alkylidenefuran-2-ones is less well studied. Aside from the traditional cyclodehydration of g-keto acids and subsequent aldol condensation with aromatic aldehydes, few routes have been reported by means of the transition-metal-cata-lyzed cyclization of appropriately functionalized acetylenic substrates (Scheme 1).…”