Bio‐inspired Small Molecular Catalysis

Abstract

Comprehensive Summary Nature is an inspiring resource for chemists to exploit uncharted chemical spaces. Enzymes in nature are characteristic of high efficiency and exquisite stereocontrol under rather mild conditions. Not surprisingly, chemists have a long history in developing new catalysts by learning from and imitating the natural enzymes. This review summarizes our long‐standing efforts in developing bio‐inspired small molecular catalysis. These were categorized according to the employed strategies: 1) bi‐/multi‐functional strategy for the bio‐inspired chiral primary amine catalyst; 2) cofactor strategy for bio‐inspired ortho‐quinone catalyst; 3) intermediate strategy for chiral latent carbocation catalysis based on natural carbocation process. Each section includes brief introduction of the biological origin, design of catalyst, development of methodology as well as the underlying mechanistic insights. What is the most favorite and original chemistry developed in your research group? I hope it's always the next one. How do you get into this specific field? Could you please share some experiences with our readers? Nature provides many astonishing catalytic machineries for building up molecular complexity and harnessing energy in the most efficient ways. Nature's recipe for catalysis serves as a starting point to develop new catalyst for synthetic and energy chemistry. I was trained as a synthetic chemist in a physical organic group in Nankai and ICCAS, and spent part of my graduate studies doing enzymatic synthesis of oligosaccharide and its related biological applications in Ohio State University. This gave me a mixed view on organocatalysis, then under its golden stage of renaissance, not only for its synthetic potentials as a new catalytic concept, but also with an eye on its biological origin and possible impact beyond synthesis. I also benefit a lot from the physical organic chemistry training which helps to shape my research path in width and depth, in a way I never imagined and expected at the beginning of my career. How do you supervise your students? Try to inspire beyond instruct. I learned and am still learning. “因材施教” is easy to say than to do. In reality, I become bossy the way I dislike and have to instruct heavily. What is the most important personality for scientific research? Curiosity, broad reading and sufficient “free time” for daydreaming. In order to have enough time to waste, you have to work really hard at first. Who influences you mostly in your life? My Ph.D. supervisor, Prof. Jin‐Pei Cheng who teaches me a rational and quantitative view for chemistry and inspires me all the time to pursue a rational approach in research.

Enantioselective Transformations by “1 + x” Synergistic Catalysis with Chiral Primary Amines

“…22,23 In the past few years, we have endeavored much effort in exploring primary amine-based synergistic catalysis. 24,25 One type of vicinal chiral primary−tertiary diamine catalyst has been found to work synergistically or cooperatively with a number of transition metal catalysts, such as Pd, Rh, Ag, Co, and Cu; as well as other organocatalysts, such as B(C 6 F 5 ) 3 , ketone, selenium, and iodide; photocatalysis; and electrochemical processes. In this unique "1 + x" synergistic scenario, the secondary enamine intermediate can be modulated with respect to all three major properties (Scheme 1I−III), by the joint force with its catalytic partners.…”

“…Both secondary and primary aminocatalysts have been widely examined and have proved to be viable for synergistic catalysis. , However, a single type of aminocatalyst able to incorporate all different synergistic strategies is still very rare. Previously, we reported chiral primary–tertiary vicinal diamines as a functional and mechanistic mimic of Type I aldolase. , In the past few years, we have endeavored much effort in exploring primary amine-based synergistic catalysis. , One type of vicinal chiral primary–tertiary diamine catalyst has been found to work synergistically or cooperatively with a number of transition metal catalysts, such as Pd, Rh, Ag, Co, and Cu; as well as other organocatalysts, such as B­(C 6 F 5 ) 3 , ketone, selenium, and iodide; photocatalysis; and electrochemical processes. In this unique “1 + x ” synergistic scenario, the secondary enamine intermediate can be modulated with respect to all three major properties (Scheme I–III), by the joint force with its catalytic partners.…”

Production of esters with numerous applications: Kinetics of Dowex 50W catalyzed transesterification of methyl acetate with three‐ and four‐carbon structured alcohols

“…Methyl acetate applications are limited and its economic value is moderate. [ 1 ] Therefore, many investigations are carried out to convert it to more valuable products of longer‐chain alkyl acetate. [ 1–9 ] Methyl acetate can be converted to other alkyl easters such as n ‐propyl acetate and n ‐butyl acetate that have more applications and higher economical value via transesterification reactions.…”

“…[ 1 ] Therefore, many investigations are carried out to convert it to more valuable products of longer‐chain alkyl acetate. [ 1–9 ] Methyl acetate can be converted to other alkyl easters such as n ‐propyl acetate and n ‐butyl acetate that have more applications and higher economical value via transesterification reactions. Although these alkyl acetates can be produced directly through esterification reactions, the transesterification path is considered mild and versatile in comparison to esterification.…”

Visible Light-Promoted Enantioselective Aerobic Hydroxylation of β-Ketocarbonyls by Chiral Primary Amine Catalysis

“…Previously, it is known that the reaction with singlet oxygen could be promoted by a favorable H-bonding . In our model, the protonated tertiary amine would direct Re -facial attack of enamine to 1 O 2 , which is also hydrogen-bonded by HFIP (Scheme , below). The dual hydrogen-bonding network would significantly enhance the polarity of 1 Δ g state of 1 O 2 , thus promote the nucleophilic C–O bond formation process.…”