RESUMEN

Hepatic cystadenoma is a rare disease, accounting for about 5% of all cystic lesions, with a high tendency of malignant transformation. The preoperative diagnosis of cystadenoma is difficult, and some cystadenomas are easily misdiagnosed as hepatic cysts at first. Hepatic cyst is a relatively common liver disease, most of which are benign, but large hepatic cysts can lead to pressure on the bile duct, resulting in abnormal liver function. To better understand the difference between the microenvironment of cystadenomas and hepatic cysts, we performed single-nuclei RNA-sequencing on cystadenoma and hepatic cysts samples. In addition, we performed spatial transcriptome sequencing of hepatic cysts. Based on nucleus RNA-sequencing data, a total of seven major cell types were identified. Here we described the tumor microenvironment of cystadenomas and hepatic cysts, particularly the transcriptome signatures and regulators of immune cells and stromal cells. By inferring copy number variation, it was found that the malignant degree of hepatic stellate cells in cystadenoma was higher. Pseudotime trajectory analysis demonstrated dynamic transformation of hepatocytes in hepatic cysts and cystadenomas. Cystadenomas had higher immune infiltration than hepatic cysts, and T cells had a more complex regulatory mechanism in cystadenomas than hepatic cysts. Immunohistochemistry confirms a cystadenoma-specific T-cell immunoregulatory mechanism. These results provided a single-cell atlas of cystadenomas and hepatic cyst, revealed a more complex microenvironment in cystadenomas than in hepatic cysts, and provided new perspective for the molecular mechanisms of cystadenomas and hepatic cyst.

Asunto(s)

RESUMEN

It is very necessary for patients with liver cancer to reasonably apply the prediction method of liver failure after hepatectomy before liver surgery. Liver surgeons can benefit greatly from clinical activities.

Asunto(s)

RESUMEN

Highly enantioselective rhodium-catalyzed addition of arylboroxines to N-unprotected ketimines is realized for the first time by employing chiral BIBOP-type ligands with a Rh loading as low as 1 mol %. A range of chiral α-trifluoromethyl-α,α-diaryl α-tertiary amines or 3-amino-3-aryloxindoles were formed with excellent ee values and yields by employing either WingPhos or PFBO-BIBOP as the ligand. The method has enabled an efficient enantioselective synthesis of cipargamin.

RESUMEN

An efficient catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides with four-membered ring-containing exocyclic alkenes has been developed, and either the exo or endo spirocyclic pyrrolidine-azetidine/oxe(thie)tane derivatives were diastereodivergently generated by employing Cu(i)/tBu-Phosferrox and a Cu(i)/N,O-ligand complex, respectively. Notably, various heteroatom-containing (N, O, S) exocyclic alkenes were found to be well-tolerated in this transformation.

RESUMEN

A cascade reaction of rhodium azavinylcarbenes with Morita-Baylis-Hillman (MBH) adducts enables a novel synthetic approach to 3,4-fused pyrroles. The cascade reaction begins with the insertion of O-H bond into rhodium azavinylcarbenes, subsquent sigmatropic rearrangement provides substituted α,ß-unsaturated cyclic ketone intermediates. Then the intramolecular aza Michael addition/oxidative aromatization sequence give rise to a wide range of 3,4-fused pyrroles in good yields, and with excellent functional group compatibility.

RESUMEN

A novel protocol for the synthesis of unsymmetrical indigo-like (E)-α-amino enaminones by rhodium-catalyzed transformations of isatins with 1-tosyl-1,2,3-triazoles has been developed. A plausible reaction mechanism is proposed to account for the formation of structurally important unsymmetrical indigo analogues, which represents a new strategy for C-C bond formation based on the transformations of secondary amides and rhodium azavinylcarbenes.

RESUMEN

A practical and efficient method for divergent synthesis of 3,6-disubstituted- and 3,5,6-trisubstituted-1,2,4-triazines via unexpected rhodium-catalyzed O-H insertion/rearrangement/conditions-controlled intramolecular cyclization and oxidation reaction under mild conditions has been developed. Notably, it is the first example for the synthesis of 1,2,4-triazines with different substituted-patterns via a common intermediate with excellent chemoselectivities by the reaction of N-acylhydrazones as aze-[3C] or [4C] synthons with N-sulfonyl-1,2,3-triazoles as aze-[2C] synthons. Furthermore, this method allows direct access to di(het)aryl ketone frameworks containing 1,2,4-triazine moiety for the first time, serving as a versatile building block for the synthesis of other useful heterocyclic skeletons, such as pyridine or pyridazinone-fused triazine in excellent yields.

RESUMEN

Chalcone is a simple and potentially privileged structure in medicinal chemistry with a diverse repertoire of biological activities, among which cytotoxicity is of particular interest. The sharp structure-activity relationship (SAR) for chalcone's cytotoxicity suggests structure-specific target interactions. Despite the numerous putative targets proposed, evidence for direct target interactions in cells is unavailable. In this study, guided by the sharp cytotoxic SAR, we developed a cytotoxic chalcone-based photoaffinity labeling (PAL) probe, (E)-3-(3-azidophenyl)-1-[3,5-dimethoxy-4-(prop-2-yn-1-yloxy)phenyl]-2-methylprop-2-en-1-one (C95; IC50 : 0.38±0.01 µm), along with two structurally similar non-cytotoxic probes. These probes were used to search for the direct cellular target responsible for chalcone's cytotoxicity through intact cell-based PAL experiments, in which ß-tubulin was identified to specifically interact with the cytotoxic probe (i.e., C95) but not the non-cytotoxic probes. A set of phenotypical and biochemical assays further reinforced ß-tubulin as the cytotoxic target of chalcones. Peptide mass quantitation by mass spectrometric analysis revealed one peptide potentially labeled by C95, providing information on chalcone's binding site on ß-tubulin.

Asunto(s)

RESUMEN

Highly enantioselective additions of arylboroxines to simple aryl ketones have been achieved for the first time with a Rh/(R,R,R,R)-WingPhos catalyst, thus providing a range of chiral diaryl alkyl carbinols with excellent ee values and yields. (R,R,R,R)-WingPhos has been proven to be crucial for the high reactivity and enantioselectivity. The method has enabled a new, concise, and enantioselective synthesis of the antidepressant drug escitalopram.

Asunto(s)

RESUMEN

A highly efficient asymmetric 1,3-dipolar cycloaddition of azomethine ylides to 5-alkylidene thia(oxa)zolidine-2,4-diones catalyzed by a chiral N,O-ligand/Cu(CH3CN)4BF4 system is reported, affording structurally novel spirocyclic pyrrolidine-thia(oxa)zolidinediones with a spiro-heteroquaternary stereogenic center in good to excellent yields (up to 99%), with excellent levels of diastereo- and enantioselectivity (dr up to 99:1; ee up to 98%).

RESUMEN

A series of chiral N,O-ligands derived from a 1,2-dihydroimidazo[1,2-a]quinolone motif have been evaluated for the asymmetric 1,3-dipolar cycloaddition of azomethine ylides with a novel dipolarophile ß-phthalimidonitroethene. A newly designed DHIPOH ligand 7c bearing 1-methyl and 4-iodo substituents was found to have significant "synergistic steric effects" and consequently afforded the corresponding 4-nitro-3-aminopyrrolidines with excellent diastereo- (dr up to 98:2) and enantio selectivities (ee up to 99%). Subsequent Raney Ni-catalyzed reduction and deprotection of phthalyl led to the structurally and biologically important 3,4-diaminopyrrolidines in a straightforward and efficient pathway.

RESUMEN

A protocol to access useful 4-aminopyrrolidine-2,4-dicarboxylate derivatives has been developed. A variety of chiral N,O-ligands derived from 2,3-dihydroimidazo[1,2-a]pyridine motifs have been evaluated in the asymmetric 1,3-dipolar cycloaddition of azomethine ylides to α-phthalimidoacrylates. Reactions catalyzed by copper in combination with ligand 7-Cl-DHIPOH provided the highest level of stereoselectivity for the 1,3-dipolar cycloaddition reaction. The reaction tolerates both ß-substituted and ß-unsubstituted α-phthalimidoacrylate as dipolarophiles, affording the corresponding quaternary 4-aminopyrrolidine cycloadducts with excellent diastereo- (>98:2 d.r.) and enantioselectivities (up to 97 % ee). Removal of the phthalimido protecting group can be accomplished by a simple NaBH4 reduction. Theoretical calculations employing DFT methods show this cycloaddition reaction is likely to proceed through a stepwise mechanism and the stereochemistry was also theoretically rationalized.

RESUMEN

A highly efficient asymmetric 1,3-dipolar cycloaddition of azomethine ylides to α-alkylidene succinimides catalyzed by a novel chiral N,O-ligand/Cu(OAc)2 system is reported, affording dispiropyrrolidine derivatives with spiro quaternary stereogenic centers in good to excellent yields (up to 90%), excellent levels of diastereoselectivities (>20 : 1 dr) and enantioselectivities (up to 97% ee).

Asunto(s)

RESUMEN

A highly efficient nonenzymatic kinetic resolution of a series of structurally diverse racemic α-methylene-ß-hydroxy esters utilizing the acyl transfer catalyst An-PIQ and propionic anhydride is reported. This procedure provides recovered alcohols with extremely high ee's (up to >99%) in reasonable conversions and excellent selectivity factors (S up to 108). Several synthetically important substrates were resolved in gram-scale reactions, and highly optically pure α-methylene-ß-hydroxy esters were obtained with excellent S values and good yields.

Asunto(s)

RESUMEN

A novel and efficient route for the preparation of 4-carboxylated isoquinolines via a Ag(I) and Cu(I) cocatalyzed tandem reaction of 2-alkynylbenzaldoximes with aldehydes or alcohols in moderate to good yields is described. The reaction proceeds smoothly to produce C-N and C-O bonds in a one-pot procedure with structural complexity and molecular diversity.

Asunto(s)

RESUMEN

Cyclization reactions of alkynes, especially the double carbometallation of alkynes, have drawn much interest from organic chemists because of their high efficiency in the construction of polycycles. Utilizing different nucleophiles or catalytic systems, various efficient strategies to access challenging skeletons have been extensively explored in recent years. In this review, achievements in this field are presented in three major parts (the syn-syn, anti-anti, and syn-anti addition reactions of diynes or two alkyne molecules). Cyclization reactions of diynes initiated by nucleophiles, [2+2+n] cycloaddition, or other processes and reactions, involving two identical or different alkynes are described, which provide facile and reliable approaches to various π systems, medium-sized rings, and even macrocycles.

Asunto(s)

RESUMEN

A tandem reaction between N'-(2-alkynylbenzylidene)hydrazide and cycloprop-2-ene-1,1-dicarboxylate co-catalyzed by silver triflate and tris(triphenylphosphine)rhodium chloride is reported. The reaction proceeds through 6-endo-cyclization, [3 + 2] cycloaddition, cyclopropane opening, and aromatization, leading to pyrazolo[5,1-a]isoquinolines in moderate to good yields.

Asunto(s)

RESUMEN

A silver triflate-catalyzed tandem reaction of N'-(2-alkynylbenzylidene)hydrazide with pyridyne is presented. Different outcomes are obtained, depending on the pyridynes utilized in the transformation.

Asunto(s)

RESUMEN

A three-component reaction of 2-alkynylbenzaldehyde, sulfonohydrazide, and nitrile catalyzed by silver triflate under mild conditions is reported, which generates pyrazolo[5,1-a]isoquinolin-2-amines in good to excellent yields.

Asunto(s)

RESUMEN

Diverse 2H-isoindol-1-ylphosphonates as potential HCT-116 inhibitors are easily generated via a FeCl(3) and PdCl(2) cocatalyzed three-component reaction of 2-alkynylbenzaldehyde, aniline, and phosphite. The focused small library is constructed based on parallel diversity-oriented synthesis.

Asunto(s)