370562-34-8

Upstream product

• 186581-53-3 diazomethane 
• 128550-08-3 2-[1-(tert-butyloxycarbonyl)-1H-indol-3-yl]acetic acid 
• 67-56-1 methanol 
• 87-51-4 indole-3-acetic acid 
• 201230-82-2 carbon monoxide 
• 1912-33-0 Indole-3-acetic acid methyl ester 
• 24424-99-5 di-tert-butyl dicarbonate 

Relevant academic research and scientific papers

Iridium-Catalyzed Amidation of in Situ Prepared Silyl Ketene Acetals to Access α-Amino Esters

Disclosed herein is a convenient Ir-catalyzed amidation of esters to access α-amido esters. Initially prepared silyl ketene acetals are directly employed, without separate purification, for subsequent amidation with an oxycarbonylnitrenoid precursor using the Cp*(LX)Ir(III) catalyst. The α-amidation was facile for both α-aryl and α-alkyl esters. Density functional theory studies revealed that the generation of a putative Ir-nitrenoid is facilitated by the chelation of the countercation additive during the N-O bond cleavage of the nitrene precursor.

Electrochemical Dearomative Dicarboxylation of Heterocycles with Highly Negative Reduction Potentials

The dearomative dicarboxylation of stable heteroaromatics using CO2is highly challenging but represents a very powerful method for producing synthetically useful dicarboxylic acids, which can potentially be employed as intermediates of biologically active molecules such as natural products and drug leads. However, these types of transformations are still underdeveloped, and concise methodologies with high efficiency (e.g., high yield and high selectivity for dicarboxylations) have not been reported. We herein describe a new electrochemical protocol using the CO2radical anion (E1/2of CO2= -2.2 V in DMF and -2.3 V in CH3CN vs SCE) that produces unprecedented trans-oriented 2,3-dicarboxylic acids from N-Ac-, Boc-, and Ph-protected indoles that exhibit highly negative reduction potentials (-2.50 to -2.94 V). On the basis of the calculated reduction potentials, N-protected indoles with reduction potentials up to -3 V smoothly undergo the desired dicarboxylation. Other heteroaromatics, including benzofuran, benzothiophene, electron-deficient furans, thiophenes, 1,3-diphenylisobenzofuran, and N-Boc-pyrazole, also exhibit reduction potentials more positive than -3 V and served as effective substrates for such dicarboxylations. The dicarboxylated products thus obtained can be derivatized into useful synthetic intermediates for biologically active compounds in few steps. We also show how the dearomative monocarboxylation can be achieved selectively by choice of the electrolyte, solvent, and protic additive; this strategy was then applied to the synthesis of an octahydroindole-2-carboxylic acid (Oic) derivative, which is a useful proline analogue.

Photoinduced Diverse Reactivity of Diazo Compounds with Nitrosoarenes

A diverse reactivity of diazo compounds with nitrosoarene in an oxygen-transfer process and a formal [2 + 2] cycloaddition is reported. Nitosoarene has been exploited as a mild oxygen source to oxidize an in situ generated carbene intermediate under visible-light irradiation. UV-light-mediated in situ generated ketenes react with nitosoarenes to deliver oxazetidine derivatives. These operationally simple processes exemplify a transition-metal-free and catalyst-free protocol to give structurally diverse α-ketoesters or oxazetidines.

New Series of Potent Allosteric Inhibitors of Deoxyhypusine Synthase

Deoxyhypusine synthase (DHPS) is the primary enzyme responsible for the hypusine modification and, thereby, activation of the eukaryotic translation initiation factor 5A (eIF5A), which is key in regulating the protein translation processes associated with tumor proliferation. Although DHPS inhibitors could be a promising therapeutic option for treating cancer, only a few studies reported druglike compounds with this inhibition property. Thus, in this work, we designed and synthesized a new chemical series possessing fused ring scaffolds designed from high-throughput screening hit compounds, discovering a 5,6-dihydrothieno[2,3-c]pyridine derivative (26d) with potent inhibitory activity; furthermore, the X-ray crystallographic analysis of the DHPS complex with 26d demonstrated a distinct allosteric binding mode compared to a previously reported inhibitor. These findings could be significantly useful in the functional analysis of conformational changes in DHPS as well as the structure-based design of allosteric inhibitors.

Enantio- and Site-Selective α-Fluorination of N-Acyl 3,5-Dimethylpyrazoles Catalyzed by Chiral π–CuII Complexes

Catalytic enantioselective α-fluorination reactions of carbonyl compounds are among the most powerful and efficient synthetic methods for constructing optically active α-fluorinated carbonyl compounds. Nevertheless, α-fluorination of α-nonbranched carboxylic acid derivatives is still a big challenge because of relatively high pKa values of their α-hydrogen atoms and difficulty of subsequent synthetic transformation without epimerization. Herein we show that chiral copper(II) complexes of 3-(2-naphthyl)-l-alanine-derived amides are highly effective catalysts for the enantio- and site-selective α-fluorination of N-(α-arylacetyl) and N-(α-alkylacetyl) 3,5-dimethylpyrazoles. The substrate scope of the transformation is very broad (25 examples including a quaternary α-fluorinated α-amino acid derivative). α-Fluorinated products were converted into the corresponding esters, secondary amides, tertiary amides, ketones, and alcohols with almost no epimerization in high yield.

PHOTOPROTECTIVE COMPOSITIONS CONTAINING MALASSEZIA-DERIVED COMPOUNDS AND/OR CHEMICAL ANALOGS THEREOF

The present invention relates to compounds, compositions, and methods for modulating skin pigmentation and treating or preventing UV-induced skin damage, erythema, aging of the skin, sunburn, and hyperpigmentation in a subject. The compounds, compositions, and methods of the present invention generally involve Malassezia-derived compounds, including malassezin and indirubin, and/or chemical analogs thereof. Other applications of the compounds and compositions disclosed herein include, but are not limited to, improving hyperpigmentation caused by a hyperpigmentation disorder, inducing melanocyte apoptosis, and modulating arylhydrocarbon receptor (AhR) activity, melanogenesis, melanin production, melanosome biogenesis, melanosome transfer, melanocyte activity, and melanin concentration.

Efficient Synthesis of the Peptide Fragment of the Natural Depsipeptides Jaspamide and Chondramide

A new method for the synthesis of the tripeptide part of the jaspamide and chondramide alkaloids using a Ugi reaction was developed. The reported approach is considerably shorter than all literature syntheses of the peptide parts of these natural products. A family of peptides with different substituents at the 2-position of the indole moiety was prepared to open up access to analogues of these natural products.

Total synthesis of asterredione

The first total synthesis of asterredione was efficiently accomplished over five linear steps and in 21.5% overall yield. As the crucial step, the 2-quaternary 1,3-cyclopentenedione skeleton of asterredione was readily achieved using the Darzens/ring-expansion strategy developed in our laboratory. The structure of synthesized asterredione was fully confirmed by X-ray crystallography.

Gold-catalyzed regioselective hydration of propargyl acetates assisted by a neighboring carbonyl group: Access to α-acyloxy methyl ketones and synthesis of (±)-actinopolymorphol B

A general atom-economical approach for the synthesis of α-acyloxy methyl ketone is demonstrated through regioselective hydration of a wide range of propargyl acetates. Readily available catalyst comprising of 1% Ph 3PAuCl and 1% AgSbF6 in dioxane-H2O efficiently hydrolyzes the terminal alkynes of the propargyl acetate in the absence of acid promoters at ambient temperature within a short time. Effective regioselective hydration is facilitated by the neighboring carbonyl group as demonstrated through 18O-labeling study. Compatibility of functional moieties and tolerance to various acid-labile protecting groups are observed. The catalytic condition is also suitable to perform hydration of TMS-substituted propargyl acetates, even though it requires prolonged reaction time for completion. Stereointegrity of the propargylic acetate is preserved during the hydration. The robustness of the system is successfully demonstrated through gram scale preparation of the product in nearly quantitative yield. The common α-acyloxy methyl ketone is transformed to 1,2-diol and 1,2-amino alcohol derivatives. Synthesis of actinopolymorphol B is achieved for the first time involving hydration of the propargyl acetate as the key step.

Synthesis of the tetracyclic core skeleton of the lundurines by a gold-catalyzed cyclization

The 1H-azocino[5,4-b]indole skeleton of the lundurines has been prepared by the 8-endo-dig cyclization of an alkynylindole using AuCl3 or other gold complexes as catalysts.