Dehydration Reactions in Water. Brønsted Acid−Surfactant-Combined Catalyst for Ester, Ether, Thioether, and Dithioacetal Formation in Water

Manabe, Kei; Iimura, Shinya; Sun, Xiang‐Min; Kobayashi, Shū

doi:10.1021/ja026241j

Cited by 388 publications

(226 citation statements)

References 53 publications

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“…Cinchona ester derivatives could be obtained in high yield under DBSAcatalyzed conditions and those compounds were also found proceeding smoothly. This work not only may lead to mild environmental systems but also will serve a new aspect of organic chemistry synthesis in water [35,37,38]. By utilizing an efficient, catalytic, rapid, stable and high-yielding protocol for the cinchona alkaloids synthesis by DBSA with amphipathic Brønsted acid, this will make commercially available, highly reactive, cheap, stable, excellent emulsifier and activator very powerful in obtaining pure high yields of synthesized product.…”

Section: Resultsmentioning

confidence: 99%

In Silico Screening and Designing Synthesis of Cinchona Alkaloids Derivatives as Potential Anticancer

Hanafi

Rosmalena

Prasasty

et al. 2017

JTLS

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P-glycoprotein (P-gp) resistance in cancer cells decreases the intracellular accumulation of various anticancer drugs. This multidrug resistance (MDR) protein can be modulated by number of non-cytotoxic drugs. We have screened 30 cinchona alkaloids derivatives as a potent P-gp inhibitor agent in silico. Hereby, we report the highest potential inhibitions of P-gp is Cinchonidine isobutanoate through molecular docking approach with affinity energy -8.6 kcal/mol and inhibition constant, Ki is 4.89 × 10 -7 M. Cinchonidine isobutanoate is also known has molecular weight below 500, Log P value 3.5, which is indicated violation free of Lipinski`s rule of five. Thus, Cinchonidine isobutanoate is the most potent compound as anticancer compare to other Cinchona alkaloids. Ultimately, we design Cinchonidine isobutanoate for further lead synthesis by using DBSA, act as a combined Brønsted acid-surfactantcatalyst (BASC) to obtain a high concentration of organic product by forming micellar aggregates which are very powerful catalytic application in a water environment.

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Section: Resultsmentioning

confidence: 99%

In Silico Screening and Designing Synthesis of Cinchona Alkaloids Derivatives as Potential Anticancer

Hanafi

Rosmalena

Prasasty

et al. 2017

JTLS

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“…Instead, surfactanttype protonic acids such as dodecylbenzenesulfonic acid (DBSA) are useful. 26,28,30) Here, we report that the cyclization reaction proceeds in good yield using DBSA as a surfactanttype protonic acid catalyst.…”

mentioning

confidence: 90%

Synthesis of α-Methylene-γ-lactone Structure by Cyclization of ω-Formylallylsilane in Water

Fukushima

Ikegami

Kuroda

et al. 2018

CHEMICAL & PHARMACEUTICAL BULLETIN

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Surfactant-type protonic acid-promoted intramolecular cyclization of functionalized allylsilanes was studied in water for the synthesis of α-methylene-γ-lactone compounds. ω-Formyl-β-(acetoxymethyl)allylsilane afforded carbocyclic compounds in good yields, while the cyclization product was not obtained from the corresponding β-ethoxycarbonyl derivative. It was found that (Z)-β-(acetoxymethyl)allylsilane predominantly afforded the cis-product, while (E)-β-(acetoxymethyl)allylsilane afforded both cis-and trans-products at a ratio of almost 1 : 1. The stereoselectivity of the cyclization reaction was almost the same as a protonic acidpromoted reaction in CH 2 Cl 2 and was explained by an interaction between the C(Si)-C(alkene) bond and the carbonyl moiety. The cyclization products were converted to α-methylene-γ-lactone compounds.

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“…ii) Exposed hydrophobic clusters and patches are common on today's proteins. A study of 112 soluble monomeric proteins (78) (84,85), such as protein surfaces. Second, a major route of protein synthesis in simple organisms, such as bacteria and fungi, uses nonribosomal peptide synthetases, which do not involve mRNAs (86,87).…”

Section: "Flory Length Problem": Polymerization Processes Produce Mosmentioning

confidence: 99%

Foldamer hypothesis for the growth and sequence differentiation of prebiotic polymers

Guseva

Zuckermann

Dill

2017

Proc. Natl. Acad. Sci. U.S.A.

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It is not known how life originated. It is thought that prebiotic processes were able to synthesize short random polymers. However, then, how do short-chain molecules spontaneously grow longer? Also, how would random chains grow more informational and become autocatalytic (i.e., increasing their own concentrations)? We study the folding and binding of random sequences of hydrophobic (H) and polar (P) monomers in a computational model. We find that even short hydrophobic polar (HP) chains can collapse into relatively compact structures, exposing hydrophobic surfaces. In this way, they act as primitive versions of today's protein catalysts, elongating other such HP polymers as ribosomes would now do. Such foldamer catalysts are shown to form an autocatalytic set, through which short chains grow into longer chains that have particular sequences. An attractive feature of this model is that it does not overconverge to a single solution; it gives ensembles that could further evolve under selection. This mechanism describes how specific sequences and conformations could contribute to the chemistry-to-biology (CTB) transition.origin of life | HP model | biopolymers | autocatalytic sets A mong the most mysterious processes in chemistry is how the spontaneous transition occurred more than 3 billion years ago from a soup of prebiotic molecules to living cells. What was the mechanism of the chemistry-to-biology (CTB) transition? In this paper, we develop a model to explore how prebiotic polymerization processes might have produced long chains of proteinlike or nucleic acid-like molecules (1, 2). What polymerization processes are autocatalytic? How could they have produced long chains? Also, how might random chain sequences have become informational and self-serving? Our questions here are about physical spontaneous mechanisms, not about specific monomer or polymer chemistries. CTB Requires an Autocatalytic ProcessEarly on, it was recognized that the transition from simple chemistry to self-supporting biological behavior requires autocatalysis (i.e., some form of positive feedback or bootstrapping, in which the concentrations of some molecules become amplified and selfsustaining relative to other molecules) (3-8). That work has led to the idea of an autocatalytic set, a collection of entities in which any one entity can catalyze another.We first review some of the key results. A class of models called Graded Autocatalysis Replication Domain (GARD) (9-11) predicts that artificial autocatalytic chemical kinetic networks can lead to self-replication, with a corresponding amplification of some chemicals over others. Such systems display some degree of inheritance and adaptability. GARD model is a subset of metabolism first models, which envision that small molecule chemical processes precede information transfer and precede the first biopolymers. Focusing on polymers, Wu and Higgs (12) developed a model of RNA chain-length autocatalysis. They envision that some of the RNA chains can spontaneously serve as polymerase ribozymes, l...

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Dehydration Reactions in Water. Brønsted Acid−Surfactant-Combined Catalyst for Ester, Ether, Thioether, and Dithioacetal Formation in Water

Cited by 388 publications

References 53 publications

In Silico Screening and Designing Synthesis of Cinchona Alkaloids Derivatives as Potential Anticancer

In Silico Screening and Designing Synthesis of Cinchona Alkaloids Derivatives as Potential Anticancer

Synthesis of α-Methylene-γ-lactone Structure by Cyclization of ω-Formylallylsilane in Water

Foldamer hypothesis for the growth and sequence differentiation of prebiotic polymers

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