Dinuclear Zinc-Catalyzed Asymmetric Tandem Reaction of α-Hydroxy-1-indanone: Access to Spiro[1-indanone-5,2′-γ-butyrolactones]

Abstract

A highly efficient method for the enantioselective build of spiro­[1-indanone-5,2′-γ-butyrolactones] has been developed through the tandem Michael/transesterification reaction of α-hydroxy-1-indanone and α,β-unsaturated esters. A broad range of spiro­(1-indanone-butyrolacones) with contiguous stereocenters have been synthesized with excellent stereoselectivities (up to >20:1 dr, up to >99% ee) under the catalysis of dinuclear zinc complex. Moreover, the reaction can be run on a gram scale without affecting its stereoselectivities. A possible mechanism is proposed.

Catalytic Asymmetric Synthesis of Tetrahydrofuran Spirooxindoles via a Dinuclear Zinc Catalyst

“…Based on the absolute structure of product 3al and previous reports on the mechanism of dinuclear zinc catalysis, ,, a proposed catalytic cycle was suggested in order to rationalize the observed asymmetric induction (Scheme ). At first, dinuclear zinc complex I was generated in situ from the treatment of ligand L2e with 2 equiv of ZnEt 2 .…”

“…Through continuous study of the applications of dinuclear metal catalysts based on the chiral multidenate semi-azacrown ether ligands L1–L3 and ZnEt 2 (Scheme ), which led to a number of efficient catalytic enantioselective transformations, − we discovered that α-hydroxy carbonyl compounds showed good nucleophilic behavior in the presence of dinuclear zinc catalysts, which provided an ideal active site architecture . This reactivity offered efficient pathways for the preparation of versatile, optically enriched molecules, such as multisubstituted five-membered oxygen heterocycles, α,β -dihydroxy γ-keto esters, β,β -diaryl-α-hydroxy ketones, bispirotetrahydrofuran oxindoles, and spirocyclic indanone-γ-butyrolactones…”

Asymmetric Zinc Catalysis in Green One-pot Processes

“…Moreover, variously Nsubstituted ketoamides all proceeded smoothly. In the same year, these authors employed the dinuclear zinc complex Zn 2 Et((S,S)-AzePhenol), in situ generated from 5 mol% of (S,S)-AzePhenol and 10 mol% of ZnEt 2 , to catalyze an enantioselective domino Michael/lactonization reaction between 2-hydroxy-1-indanones 40 and phenyl α,β-unsaturated esters 3 [45]. Performed at 55 °C in THF as a solvent, the process afforded a range of variously substituted chiral spiro[1-indanone-5,2′-γ-butyrolactones] 44 as almost single diastereomers (>90% de) in uniformly high yields (76-92%) and remarkable enantioselectivities (95->99% ee), as presented in Scheme 13.…”

Divergent Asymmetric Reactions of ortho‐Quinone Methides with α‐Thiocyanato Indanones for the Synthesis of Spiro‐ and Fused‐Indanones

“…In this regard, 1‐indanone β‐ketone esters are the common used substrates for the preparation of spirolactones [3a, b] . Recently, α‐hydroxyl and α‐isothiocyanato1‐indanones were also demonstrated to be the efficient nucleophilic reagents to construct spiroindanone derivatives [3c–f] . In contrast, the synthesis of chiral fused indanone derivatives still involves long procedures, and to the best of our knowledge, the direct catalytic asymmetric synthesis has not yet been established.…”