Spatiotemporal control for integrated catalysis

Abstract

Integrated catalysis is an emerging methodology that can streamline the multistep synthesis of complicated products in a single reaction vessel, achieving a high degree of control and reducing the waste and cost of an overall chemical process. Integrated catalysis can be defined by the use of spatial and temporal control to couple different catalytic cycles in one pot. This primer discusses commonly employed approaches and their underlying mechanisms, and elaborates on how the integration of spatially and temporally controlled catalysis in one pot can deliver the synthesis of complex products with high efficiency. We highlight recent advances, analyze current applications and limitations, and provide an outlook for the future development of integrated catalysis. surface, [28][29][30][31][32][33][34][35] or by taking advantage of microscopic concentration gradients. 18,20,36,37 By preventing incompatible species from coming into contact with each other, efficient integrated processes may be promoted. In addition to spatial control, introducing temporal control can also alleviate compatibility concerns. If two processes compete with or hinder each other's activity, deactivating one while the other is active can help avoid incompatibility. Temporal control may be achieved using a variety of external stimuli [38][39][40][41] to switch between different states of a catalyst that have orthogonal reactivity [G] toward certain substrates.

Tuning Electrode Reactivity through Organometallic Complexes

“…200,203,206−211 Compatibility, unfortunately, remains a major obstacle toward integrating multiple catalytic events in one system. 212 Nonetheless, a polymerization catalyzed by a palladium catalyst was integrated with electrochemical CO 2 reduction to CO, demonstrating the construction of polymeric material from a simple building block like CO 2 . 213 Nonalternating polyketones with tunable CO content were obtained based on the applied current density.…”

“… A similar strategy was applied using a bifunctional cobalt-modified electrode to achieve simultaneous CO 2 reduction and water splitting . Other organic reactions also attempted paired electrolysis to conserve energy. , Integrate multistep transformations with multifunctional or interdisciplinary catalysts Upcycling of activated small molecules from electrochemical transformations such as CO 2 reduction via a single-step process remains challenging in many cases. , However, the use of multifunctional or several catalysts (homogeneous, heterogeneous, enzymatic, or photocatalyst) to conduct multistep transformations presents an attractive alternative. ,,− Compatibility, unfortunately, remains a major obstacle toward integrating multiple catalytic events in one system . Nonetheless, a polymerization catalyzed by a palladium catalyst was integrated with electrochemical CO 2 reduction to CO, demonstrating the construction of polymeric material from a simple building block like CO 2 .…”

Regulating Access to Active Sites via Hydrogen Bonding and Cation–Dipole Interactions: A Dual Cofactor Approach to Switchable Catalysis

“…In biological systems, catalytic reactions are often modulated by “gating” mechanisms that regulate substrate access to active sites based on allosteric interactions between enzymes and small molecule or ion cofactors. − Synthetic chemists have long sought to replicate allosteric gating to achieve controlled or switchable catalysis in artificial systems. − The most common gating mechanisms involve physical blocking groups, such as supramolecular constructs with switchable steric bulk or supramolecular cages with switchable access, catalyst solubility, and configurational changes like cis/trans isomerization or metal–ligand bond-breaking reactions. ,− These designs have enabled breakthroughs in copolymer synthesis, established methods for switching product selectivity in small-molecule synthesis without needing to synthetically modify the catalyst, and enhanced capabilities for multicatalyst cascades. , …”

Access to Stereoblock Polyesters via Irreversible Chain-Transfer Ring-Opening Polymerization (ICT-ROP)

“…Alternatively, straightforward access to stereoblock PHAs should be possible by leveraging catalysts with distinct stereoselectivities in an integrated, multicatalytic approach. 9 While multicatalytic approaches have enabled challenging multistep organic syntheses, 10 implementing such strategies in ROP would require discrete chain-transfer events. During the synthesis of other stereospecific polyesters, intercatalyst polymeryl exchange has emerged as a distinct pathway for polymer stereo-and sequence-control in ROP, including stereoblocks (Figure 1C).…”