Catalytic Three‐Component Machinery: Control of Catalytic Activity by Machine Speed

Abstract

Three supramolecular slider-on-deck systems DS1-DS3 were obtained as two-component aggregates from the sliders S1-S3 and deck D with its three zinc porphyrin (ZnPor) binding sites.T he binding of the two-footed slider to the deck varies with the donor qualities of and the steric hindrance at the pyridine/pyrimidine (pyr) feet, and was effected by two N pyr ! ZnPor interactions.A ccordingly,t he sliders move over the three zinc porphyrins in the deck at different speeds,n amely with 32.2, 220, and 440 kHz at room temperature.The addition of N-methylpyrrolidine as an organocatalyst to DS1-DS3 generates catalytic three-component machineries.B yu sing ac onjugate addition as ap robe reaction, we observed ac orrelation between the operating speed of the slider-ondeck systems and the yields of the catalytic reaction. As the thermodynamic binding of the slider decreases,b oth the frequency of the sliding motion and the yield of the catalytic reaction increase.The connection between protein conformational dynamics and enzymatic activity has been intensely debated [1,2] because the precise spatial arrangement and high dynamics have to work together synergistically for high turnover rates in enzymes.[3] It is thus an appealing challenge to systematically use dynamic effects in artificial catalysts to speed up ap articular process. [4,5] Herein, we describe how ad ynamic slider-on-deck system can be coupled to an organocatalyst and how the sliding speed (machine speed) in this threecomponent aggregate impacts catalysis.T he results show clearly the prevalence of kinetic over thermodynamic factors in the liberation of catalyst into solution and highlight the usefulness of dynamic multicomponent machinery.Although most biological machine archetypes are multiprotein complexes,very few examples of artificial devices [6][7][8][9][10][11][12][13][14][15][16][17][18] that arise from the self-sorting of diverse components [19][20][21] have been reported, quite in contrast to the large gamut of known covalently or topologically constructed machines. [23][24][25][26][27][28][29][30][31] Forthe present study,wechose the two-component slideron-deck systems DS1-DS3 = D·(S1-S3)( Scheme 1) for the following reasons:1)InDS1-DS3,the two-footed sliders S1-S3 should move quickly on the D 3h -symmetric deck D with its three identical zinc porphyrin (ZnPor) binding sites.2 )The speed should be adjustable by changing the binding foot of S1-S3.3 )The addition of one equiv of an organocatalyst to DS1-DS3 is expected to generate the catalytic three-component machinery cat·D·(S1-S3). 4) Thes lidersf oot (various pyridine/pyrimidine derivatives:p yr) and the organocatalyst should have comparable affinity towards the binding sites of the deck, so that liberation of the catalyst into solution may be triggered by the motion of the slider. 5) Thea mount of catalyst in solution shall be quantifiable through ac atalytic process.T hereby,s ignificantly different sliding speeds in DS1-DS3 should lead to divergent yields in the catalytic reaction.B...

Dynamic Functional Molecular Systems: From Supramolecular Structures to Multi‐Component Machinery and to Molecular Cybernetics

“…A recent example from our group highlights the synergistic action of two devices, i. e. a nanoslider aggregate and an organocatalyst . The nanoslider aggregate 22 ⋅ 23 is composed of the tris(zinc porphyrin) deck 22 on which the biped slider 23 moves at high speed (Chart 5).…”

“…In contrast, N ‐methylpyrrolidine ( 24 ) is a well‐known organocatalyst for many organic transformations, e. g. for conjugate addition reactions. When we interconnect the action of both in a spatiotemporal manner, i. e. the sliding motion of 22 ⋅ 23 and the catalytic action of N ‐methylpyrrolidine, then the outcome reveals a novel feature (Figure ): the higher the speed of the nanoslider 22 ⋅ 23 the higher is the conversion of the catalytic system . This finding was rationalized as a result of a dynamic allosteric effect on the release of catalyst that is bound at the third, formally not biped‐loaded zinc porphyrin of deck 22 .…”

“… Reaction (1) tested in presence of static zinc porphyrin (ZnPor) or in presence of 22 ⋅ 23 . With increasing speed of the nanoslider assemblies, the yield (e. g. at 50 °C) was increased . Adapted with permission from Wiley‐VCH, copyright Wiley‐VCH 2018.…”

“…In detail, the first self-sorting step leads to NetState I, as the reaction of copper(I) ions and ligands With increasing speed of the nanoslider assemblies, the yield (e. g. at 50 8C) was increased. [39] Adapted with permission from Wiley-VCH, copyright Wiley-VCH 2018. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 NetState II) is the 2 : 1 mixture of [Zn(33)] 2 + and [Cu 2 (34)(23 a)] 2 + .…”

“…A recent example from our group highlights the synergistic action of two devices, i. e. a nanoslider aggregate and an organocatalyst. [39] The nanoslider aggregate 22 · 23 is composed of the tris(zinc porphyrin) deck 22 on which the biped slider 23 moves at high speed (Chart 5). Depending on the donor quality of and steric shielding about the feet of the biped the nanoslider shows exchange rates of 32 (in 22 · 23 a), 220 (in 22 · 23 b) and 440 kHz (in 22 · 23 c) at room temperature.…”