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The 1,3-dipolar cycloaddition of 2-alkylidene-1-indanone with azomethine ylides has been developed successfully promoted by simple imidazolium salts to construct a variety of spirocycles containing highly substituted pyrrolidines efficiently, affording the corresponding compounds in excellent yields (up to 99%). The highly efficient catalytic system exhibited broad substrate scopes under mild conditions.Highly substituted pyrrolidines are prevalent in many natural products which exhibit a broad range of biological and pharmaceutical activities.1 In particular, highly substituted pyrrolidine motifs containing a spiro quaternary stereogenic carbon center and fused with 1-indanone are versatile synthetic motifs for the biologically active natural products and pharmaceuticals.2 The signicance of those molecules has stimulated intensive interests to develop numerous excellent manufacturing approaches.3,4 Among them, 1,3-dipolar cycloaddition of 2-alkylidene-1-indanone with azomethine ylides is an extremely powerful and efficient strategy for the construction of spiro[pyrrolidine-1-indanone] derivatives and widely applied in organic synthesis.5 Wang 6 reported the rst example of 1,3-dipolar cycloaddition reaction of 2-alkylidene-ketones with azomethine ylide using Ag(I)/TF-BiphamPhos complex. To the best of our knowledge, no successful and efficient organocatalytic protocols for the 1,3-dipolar cycloaddition reaction of 2-alkylidene-1-indanone with azomethine ylides have been reported. And it is still highly challenging and desirable to develop new efficient catalytic systems for this transformation. 4Ionic liquids, which are powerful tools to activate donors or acceptors, can be designed for task-specic applications through smart choice of the respective cation and/or anion. 7Since the last century, ionic liquids (ILs) have been attracting organic chemists' attentions because of their advantages of friendly to environment, convenient to use, controlled properties and thermal stability.8 Especially, functionalized ILs, such as acidic, basic and other ionic liquids have been synthesized and used to promote various chemical reactions.9 Although several kinds of functionalized ILs have been used for excellent catalysts for a number of reactions, 10 such as Michael addition, 11 Diels-Alder addition 12 etc., rarely functionalized ILs were applied to 1,3-dipolar cycloaddition of 2-alkylidene-1-indanone with azomethine ylides.Herein, as a part of our program to explore the potential of functional ILs in chemical transformations, we described the rst 1,3-dipolar cycloaddition reaction of 2-alkylidene-1-indanone with various azomethine ylide promoted by imidazolium salts, one kind of simple and useful functionalized ILs, for the synthesis of spiro heterocyclic compounds containing highly substituted pyrrolidine and 1-indanone motifs with excellent results.For investigation on 1,3-dipolar cycloaddition of 2-alkylidene-1-indanone with azomethine ylides, we choose 2-alkylidene-1-indanone (1a) and azomethine ylide (2a) as mode...

Two hydrogenation mechanisms, transfer and catalytic hydrogenation, were combined to achieve higher regulation of hydrogenation chemoselectivity of cinnamyl aldehydes. Transfer hydrogenation with ammonia borane exclusively reduced C=O bonds to get cinnamyl alcohol, and Pt‐loaded metal–organic layers efficiently hydrogenated C=C bonds to synthesize phenyl propanol with almost 100 % conversion rate. The hydrogenation could be performed under mild conditions without external high‐pressure hydrogen and was applicable to various α,β‐unsaturated aldehydes.