Heteroleptic metallosupramolecular aggregates / complexation for supramolecular catalysis

Abstract

Supramolecular catalysis is reviewed with an eye on heteroleptic aggregates/complexation. Since most of the current metallosupramolecular catalytic systems are homoleptic in nature, the idea of breaking/reducing symmetry has ignited a vivid search for heteroleptic aggregates that are made up by different components. Their higher degree of functional diversity and structural heterogeneity allows, as demonstrated by Nature by the multicomponent ATP synthase motor, a more detailed and refined configuration of purposeful machinery. Furthermore, (metallo)supramolecular catalysis is shown to extend beyond the single "supramolecular unit" and to reach far into the field and concepts of systems chemistry and information science.

Keywords: heteroleptic complexation; information science; supramolecular catalysis; switching catalysis; systems chemistry.

Figure 1

Butterfly 1 (Figure was reprinted with permission from [45]. Copyright 2012 American Chemical Society. This content is not subject to CC BY 4.0.). Six-pointed star 2 = [Cd₂₁L₃₃L’₆] (Figure was reprinted with permission from [46]. Copyright 2019 American Chemical Society. This content is not subject to CC BY 4.0.). Hexagonal supramolecular nut 3 (Figure was reprinted with permission from [47]. Copyright 2016 American Chemical Society. This content is not subject to CC BY 4.0.). Cantellated tetrahedron 4 = Pd₁₂L₁₂L’₁₂ (Fujita 2014 [48]).

Figure 2

Synthesis of the three-component heteroleptic molecular boat 8 and its use as a catalyst for the Knoevenagel condensation reaction of 9 + 10. Redrawn from [58].

Figure 3

Synthesis of the two-component triangle 14 and three-component heteroleptic prism 15 [59]. Figure was adapted with permission from [59]. Copyright 2016 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 4

Catalytic Michael addition reaction using the urea-decorated molecular prism 15 [59].

Figure 5

Self-assembly of two-component tetragonal prismatic architectures with different cavity size. Figure was adapted from [65]. (Published by the Royal Society of Chemistry, “Self-assembled metallasupramolecular cages towards light harvesting systems for oxidative cyclization“, © 2021 A. Kumar et al., distributed under the terms of the Creative Commons Attribution 3.0 Unported License, https://creativecommons.org/licenses/by/3.0).

Figure 6

Construction of artificial LHS using rhodamine B as an acceptor and 24b as donor generating a photocatalyst. Figure was adapted from [65]. (Published by the Royal Society of Chemistry, “Self-assembled metallasupramolecular cages towards light harvesting systems for oxidative cyclization“, © 2021 A. Kumar et al., distributed under the terms of the Creative Commons Attribution 3.0 Unported License, https://creativecommons.org/licenses/by/3.0).

Figure 7

Synthesis of supramolecular spheres with varying [AuCl] concentration inside the cavity. Figure was adapted from [72], R. Gramage-Doria et al., “Gold(I) Catalysis at Extreme Concentrations Inside Self-Assembled Nanospheres”, Angewandte Chemie, International Edition, with permission from John Wiley and Sons. Copyright © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. This content is not subject to CC BY 4.0.

Figure 8

Hydroalkoxylation reaction of γ-allenol 34 in the presence of [AuCl]-encapsulated molecular spheres [72].

Figure 9

Two-component heteroleptic triangles of different size containing a BINOL functionality. Figure was adapted with permission from [75]. Copyright 2020 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 10

Asymmetric conjugate addition of chalcone 42 with trans-styrylboronic acid (43) catalyzed by BINOL-functionalized triangle (S)-40 [75].

Figure 11

Encapsulation of monophosphoramidite-Rh(I) catalyst into a heteroleptic tetragonal prismatic cage 47 and its use in a stereoselective hydroformylation. Figure was adapted with permission from [77]. Copyright 2015 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 12

(a) Representations of the basic HETPYP, HETPHEN, and HETTAP complex motifs. (b) The three-component rotor 52 built on zinc(II) HETTAP and N_py → ZnPor coordination motifs [89].

Figure 13

Two representative four-component rotors, with a (top) two-arm stator and (bottom) a four-arm stator. Figure was adapted with permission from [90]. Copyright 2013 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 14

Four-component rotors with a monohead rotator. Figure was adapted with permission from [94]. Copyright 2018 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 15

(left) Click reaction catalyzed by rotors [Cu₂(55)(60)(X)]²⁺. (right) Yield as a function of the rotational frequency. Figure was adapted with permission from [94]. Copyright 2018 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 16

A supramolecular AND gate. a) In truth table state (0,0) two nanoswitches serve as the receptor ensemble. Inputs for the AND gate are Zn²⁺ and Hg²⁺. b) In truth table state (1,1), copper(I) ions are released that assemble the rotating catalyst [Cu₂(55)(60)(73)]²⁺ the latter enabling the click reaction of 74 + 75. For structure of compound 55, see Figure 13. Figure was adapted with permission from [95]. Copyright 2020 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 17

Two supramolecular double rotors (each has two rotational axes) and reference complex [Cu(78)]⁺ for catalysis. Figure is a derivative work from [96]. (Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, © 2020 Goswami, A.; Schmittel, M. distributed under the terms of the Creative Commons Attribution 4.0 International License, https://creativecommons.org/licenses/by/4.0).

Figure 18

The slider-on-deck system (82•X) (X = 83, 84, or 85). Figure is from [98] and was reprinted from the journal Angewandte Chemie, International Edition, with permission from John Wiley and Sons, (“Catalytic Three-Component Machinery: Control of Catalytic Activity by Machine Speed“ by Paul, I.; Goswami, A.; Mittal, N.; Schmittel, M.), Copyright © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. This content is not subject to CC BY 4.0.

Figure 19

Catalysis of a conjugated addition reaction in the presence of the slider-on-deck system (82•X) (X = 83, 84, or 85) [98]. No catalysis was observed with the static reference 89•90.

Figure 20

A rotating catalyst builds a catalytic machinery. For catalysis of the catalytic machinery, see Figure 21. Figure was adapted from [100] (“Evolution of catalytic machinery: three-component nanorotor catalyzes formation of four-component catalytic machinery“ by Goswami, A. et al., © The Royal Society of Chemistry 2021, distributed under the terms of the Creative Commons Attribution-NonCommercial 3.0 Unported License, https://creativecommons.org/licenses/by-nc/3.0/). This content is not subject to CC BY 4.0.

Figure 21

Catalytic machinery. Figure was adapted from [100] (“Evolution of catalytic machinery: three-component nanorotor catalyzes formation of four-component catalytic machinery“ by Goswami, A. et al., © The Royal Society of Chemistry 2021, distributed under the terms of the Creative Commons Attribution-NonCommercial 3.0 Unported License, https://creativecommons.org/licenses/by-nc/3.0/). This content is not subject to CC BY 4.0.

Figure 22

An information system based on (re)shuffling components between supramolecular structures [99]. Figure was adapted with permission from [99]. Copyright 2019 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 23

Switching between dimeric heteroleptic and homoleptic complex for OFF/ON catalytic formation of rotaxanes. Figure is a derivative work from [110]. (Published by Wiley-VCH Verlag GmbH, © 2021 Ghosh, A. et al. distributed under the terms of the CC By-NC 4.0 International License, https://creativecommons.org/licenses/by-nc/4.0). This content is not subject to CC BY 4.0.

Figure 24

A chemically fueled catalytic system [112]. Figure was adapted from [112]. Copyright 2021 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 25

(Top) Operation of a fuel acid. (Bottom) Knoevenagel addition [112].

Figure 26

Development of the yield of Knoevenagel product 118 in a fueled system [112]. Figure was reprinted with permission from [112]. Copyright 2021 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 27

Weak-link strategy to increased catalytic activity in epoxide opening [119]. Figure was adapted from [24]. Copyright 2019 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 28

A ON/OFF polymerization switch based on the weak-link approach [118]. Figure was reprinted with permission from [24]. Copyright 2019 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 29

A weak-link switch turning ON/OFF a Diels–Alder reaction [132]. Figure was reprinted with permission from [24]. Copyright 2019 American Chemical Society. This content is not subject to CC BY 4.0.

Figure 30

A catalyst duo allowing selective activation of one of two catalytic acylation reactions [133] upon substoichiometric amounts of iron(II). For explanations, see text. Redrawn from reference [133].

Figure 31

A four-state switchable nanoswitch (redrawn from [134]).

Figure 32

Sequential catalysis as regulated by nanoswitch 138 and catalyst 139 in the presence of metal ions (redrawn from [134]).

Figure 33

Remote control of ON/OFF catalysis administrated by two nanoswitches through ion signaling (redrawn from [135]).