Iridium(III)‐Catalyzed Approach for the Synthesis of Fused Arenes: Access to Isoindolines, Indanes, and Dihydroisobenzofurans

Abstract

A facile and efficient method for the synthesis of isoindoline, indane, and dihydroisobenzofuran derivatives has been developed through the application of a halogen‐bridged iridium(III) complex to the [2+2+2] cycloaddition of α,ω‐diynes with alkynes. The cycloaddition tolerates a broad range of substitution groups, such as alcohol, alkyl, ether, and halogen, and the chemistry can be extended to prepare the corresponding borylated fused arenes. The reaction shows that hindered starting materials are also good partners, which provide the desired fused arenes in good yields.

Recent Advances in the Synthesis of Indanes and Indenes

“…Metal‐catalyzed [2+2+2] cyclotrimerization was reported to afford indane derivatives under suitable conditions. For example, indanes 113 were recently synthesized by Ir‐catalyzed [2+2+2] cyclotrimerization of diynes 112 with simple and functionalized 1‐alkynes, as shown in Scheme . A mixture of ortho ‐ and meta ‐substituted products were formed starting from internal alkynes …”

“… Synthesis of indane derivatives 113 by Ir‐catalyzed [2+2+2] cyclotrimerization of diynes 112 with simple and functionalized 1‐alkynes …”

“…For example, indanes 113 were recently synthesized by Ir-catalyzed [2+ +2+ +2] cyclotrimerization of diynes 112 with simple and functionalized 1-alkynes, as showni nS cheme 45. [55] Am ixture of ortho-a nd meta-substituted products were formed starting from internal alkynes. [55] The diyne substrate can also be supported on as olid resin, as shown in Scheme 46 for the reactionb etween 114 with alkynes, performed under the catalysis of [Cp*RuCl(cod)].C leavage followed by oxidation led to the formation of 1-indanones 115 (Scheme 46).…”

“…[55] Am ixture of ortho-a nd meta-substituted products were formed starting from internal alkynes. [55] The diyne substrate can also be supported on as olid resin, as shown in Scheme 46 for the reactionb etween 114 with alkynes, performed under the catalysis of [Cp*RuCl(cod)].C leavage followed by oxidation led to the formation of 1-indanones 115 (Scheme 46). [56] The methodw as successfully applied in the total synthesis of an indanone marine natural product.…”

“…Synthesis of indane derivatives 113 by Ir-catalyzed [2+ +2+ +2] cyclotrimerization of diynes 112 with simple and functionalized 1-alkynes. [55] Scheme46. Synthesis of 1-indanones 115 by Ru-catalyzed [2+ +2+ +2] cyclotrimerization of diynes 114 with alkynes,f ollowed by cleavage and oxidation.…”