An ew wayo fi ntroducingaN-heterocyclic carbene cap onto cyclodextrinsh as been devised. The benzimidazolium intermediatesw ere found to behavea s receptors towards cavity matching anions. The corresponding C 1 -a nd C 2 -symmetrical regioisomericc arbene gold(I) complexes have been tested in ab enchmark asymmetric cycloisomerization of 1,6-enynes. Up to 50 % ee was achieved for the enantioselectivec ycloisomerization of N-allyl-4-methyl-N-(3-phenylprop-2-yn-1-yl)benzenesulfonamide.Confining cavity-shaped ligands are increasingly popular in catalysis because of their capacity to controlt he first coordination sphere of metals and in doing so produce unusual selectivities during metal-catalyzed reactions. [1] However,t heir use in asymmetric catalysis remains scarce due to the lack of suitable chiral macrocyclicr eceptors. [2] Amongst them, the naturally-occurring cyclodextrins (CDs) [3] occupy ap lace of choice as they are cheap, enantiopure, available in different sizes, and can be easily derivatized at specific locations.S of ar,m ost efforth as concentrated on asymmetric catalytic reactions taking place in water to take advantage of the host-guest properties of CDs in this medium. [4] It is only recently with the advent of new ways of functionalizing CDs [5] that ligandsw ith rigidified donor atomsh ave been able to force am etal centert or eside inside the CD cavity in organic media, resulting in very promising selectivities, in particular stereoselectivity,f or severalm etal-catalyzed reactions. [6] Achieving such ad esirable outcome in gold(I) catalysis [7] still constitutes to date ah ighly challenging targeti np articular for mononuclear complexes sincet he gold catalyticc enter needstob easc lose as possible to the selectivity-inducing steric environment as for example in helicenebased systems. [8] Such af eature can also be achievedb yc onfining N-heterocyclic carbenel igands (NHCs) derived from perbenzylated CDs, as recently shown by Sollogoub et al. [6a,e] The correspondingm ono-gold complexesg ave rise to promising enantio-and ring-size selectivities in two different enyne cycloizomerization reactions. So far,n either their permethylated counterparts, nor C 1 -symmetrical AC-capped derivatives have been tested. Having ar athera ccessible cavity compared with their benzylated analogues, such confining NHC ligandss hould be suitable for sterically more demanding enyne substrates. Moreover,f ollowing our previouss tudies on anion encapsulation in metalloCDs, [9] we wondered whether we could achieve the same properties with metal-free imidazolium-capped CDs. Herein, we present an ew way of introducingaNHC cap onto CDs, the capacity of benzimidazolium-capped, methylated CDs to behave as middle-sized anion receptors, and the catalytic properties of gold complexesd erived from both C 1 -a nd C 2symmetrical NHC-capped, methylatedC Ds in the asymmetric cycloisomerization of 1,6-enynes.Contrary to their perbenzylated analogs, permethylated CDs could not be capped with an imidazolium or benzimidazolium unit...

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