Nanodevices, harvesting the power of synthetic catalysts and enzymes to perform enantioselective synthesis inside cell, have never been reported. Here, we synthesized round bottom jar-like silica nanostructures (SiJARs) with a chemo-responsive metal-silicate lid. This was isolated as an intermediate structure during highly controlled solid-state nanocrystal-conversion at the arc-section of silica shell. Different catalytic noble metals (Pt, Pd, Ru) were selectively modified on the lid-section through galvanic reactions. And, lid aperture-opening was regulated by mild acidic conditions or intracellular environment which accommodated the metal nanocrystals and enzymes, and in turn created an openmouth nanoreactor. Distinct from the free enzymes, SiJARs performed asymmetric aldol reactions with high activity and enantioselectivity (yield > 99 %, ee = 95 %) and also functioned as the artificial catalytic organelles inside living cells. This work bridges the enormous potential of sophisticated nanocrystal-conversion chemistry and advanced platforms for new-to-nature catalysis.Evolutionary compartmentalization is the key structural feature of various organelles and cells to accommodate specific enzymes and cofactors, which effortlessly drive lifesustaining multistep biochemical cascades. [1] artificial organelle-like nanoreactors harnessing high activity of synthetic catalysts along with inherent handedness of enzymes, can result diversified platforms for bioorthogonal synthesis. [2, 3] These chemo-enzymatic systems can asymmetrically synthesize chiral enantiomeric bioactive molecules, [4] possessing distinct pharmacological and toxicological systemic responses and in turn leading to advanced bioimaging, therapeutic and biotechnological applications. [5] Variety of nature-inspired hollow nanostructures, which consist of silica/silicate [4b,c, 6] and polymers/micelles [3a, 7] confining catalytic nanocrystals (NCs), enzymes or both, have demonstrated improved catalysis that are mostly limited to abiotic conditions. [8] Microemulsion-, sacrificial template-, and one-pot entrapment-based methods for pre-encapsulation of bio/nano-catalysts inside a confining nano-housing, often involve difficult to control multiple synthetic steps, harsh conditions, biphasic non-aqueous solvents and complex reagents. [9] Major challenge to design nanoreactors for intracellular application is to reliably colocalize and maintain the reactive surfaces of catalytic NCs along with the protection of enzymes from de-activation. [4,10] In this regard, silica nanostructures are highly appealing for wide range of catalytic and biomedical applications owing to their chemical inertness, high stability, biocompatibility and synthetic flexibility. [11] Previously, we developed solid-state conversion strategy for reversible hollowing of silica-coated manganese oxide (MnO@SiO 2 ) [12] and the post-synthetic modification of the hollow silica interiors with catalytic noble metals. [13] However, these microporous closed shells restrict the entry and co-...