A series of trinuclear and dinuclear Cr(I)− N 2 complexes bearing cyclopentadienyl-phosphine ligands were synthesized and characterized. Further reduction of the Cr(I)−N 2 complexes generated anionic Cr(0)−N 2 complexes, which could react with Me 3 SiCl to afford the first chromium hydrazido complex from N 2 functionalization. These complexes were found to be effective catalysts for the transformation of N 2 into N(SiMe 3 ) 3 .

Construction of Gd(III) photosensitizers is important for designing theranostic agents owing to the unique properties arising from seven unpaired f electrons of the Gd(3+) ion. Combining these with the advantages of porpholactones with tunable NIR absorption, we herein report the synthesis of Gd(III) complexes Gd-1-4 (1, porphyrin; 2, porpholactone; 3 and 4, cis- and trans-porphodilactone, respectively) and investigated their function as singlet oxygen ((1) O2 ) photosensitizers. These Gd complexes displayed (1) O2 quantum yields (ΦΔ s) from 0.64-0.99 with the order Gd-1

SummaryAs a rapidly progressing field in oncology, the adoptive transfer of T cells that have been genetically modified with chimeric antigen receptors (CARs) has shown striking efficacy in the management of hematological malignancies and has been reported in a number of clinical trials. Of note, CAR T cell therapy has shown extraordinary potential, especially in relapsed/refractory patients. However, there are still challenges regarding the further development of this strategy, spanning from engineering and manufacturing issues, to limited applications, to accompanying toxicities. In this review, we will summarize the general knowledge of this novel method, including receptor composition, applications, adverse events and challenges. Additionally, we will propose several comprehensive recommendations.

A tricoordinated gold(I) chloride complex, tBuXantphosAuCl, supported by a sterically bulky 9,9-dimethyl-4,5-bis(di-tert-butylphosphino)xanthene ligand (tBuXantphos) was synthesized. This complex features a remarkably longer Au-Cl bond length [2.632(1) Å] than bicoordinated linear gold complexes (2.27-2.30 Å) and tricoordinated XantphosAuCl [2.462(1) Å]. Single-crystal X-ray diffraction analysis of a cocrystal of tBuXantphosAuCl and pentafluoronitrobenzene (PFNB) and UV-vis spectroscopic titration experiments revealed the existence of an anion-π interaction between the Cl anion ligand and PFNB. Stoichiometric reaction between PFNB and tBuXantphosAuOtBu, after replacement of Cl by a more nucleophilic tBuO anion ligand, showed higher reactivity and para selectivity in the transformation of C-F to C-OtBu bond, distinctively different from that when only KOtBu was used (ortho selectivity) under the identical condition. Mechanistic studies including density functional theory calculations suggested a gold-mediated nucleophilic ligand attack of the C-F bond pathway via an SNAr process. On the basis of these results, using trimethylsilyl derivatives TMS-X (X = OMe, SEt, NEt2) as the nucleophilic ligand source and the fluorine acceptor, catalytic transformation of the C-F bond of aromatic substrates to the C-X (X = O, S, N) bond was achieved with tBuXantphosAuCl as the catalyst (up to 20 turnover numbers).

Isolation of key intermediate complexes in dinitrogen functionalization is crucial for elucidating the mechanistic details and further investigation. Herein, the synthesis and characterization of (μ-η1:η1-N2)(η1-N2)-Cr(I) 3 and (η1-N2)2-Cr(0) complexes 4 supported by Cp* (Cp* = C5Me5) and NHC ligands were reported. Further functionalization of Cr(0)-N2 complex 4 with silyl halides delivered the key intermediates in the alternating pathway, the chromium diazenido complex 5 and the chromium side-on η2-hydrazido complex 6. Protonation of 6 led to the quantitative formation of N2H4. Moreover, the [η2-Me3SiNNSiMe3]2– unit in 6 enabled N–C bond formation reactions with CO2 and t BuNCO, giving the corresponding N,O-chelating hydrazidochromium complexes 7 and 8, respectively.

Aberrant microRNA expression is common in colorectal cancer and DNA methylation is believed to be responsible for this alteration. In this study, we performed evaluation in vivo and in vitro to determine the role of miR-181b as a potential diagnostic and prognostic biomarker in colorectal cancer. Ninety-seven pairs of colorectal cancer tissues and adjacent normal tissues were collected. The expression level and methylation status of miR-181b was determined in tissue samples and multiple colorectal cancer cell lines. RASSF1A, a predicted target gene of miR-181b, was investigated in vitro. Further mechanistic explorations were conducted. It was found that miR-181b expression was frequently downregulated in cancer samples. This lower expression level resulted from higher hypermethylation in cancer tissue and was closely related to TNM stage. Following artificial synthesis of miR-181b stimulation, colorectal cancer cell proliferation was greatly inhibited in CRC cells while apoptosis percentage markedly increased. miR-181b achieved the tumor suppressive effects via direct targeting of the RASSF1A gene. This study indicated the clinical significance of miR-181b and the influence of miR-181b promoter region in epigenetic silencing of tumorigenicity in colorectal cancer, and implied the possible usage of miR-181b as a diagnostic and prognostic biomarker in colorectal cancer.

The element nitrogen and nitrogenous compounds are vital to life. The synthesis of nitrogen-containing compounds using dinitrogen as the nitrogen source, not through ammonia, is of great interest and great value but remains a grand challenge. Herein, we describe a strategy to realize this transformation by combining the heterogeneous approach with the homogeneous methodology. The N2 molecule was first fixed with carbon and LiH through a one-pot heterogeneous process, forming Li2CN2 as an ‘activated’ nitrogen source with high efficiency. Then subsequent homogeneous treatments of Li2CN2 to construct the organic synthon carbodiimide and the RNA/DNA building block pyrimidines were fulfilled. By using 15N2 as the feedstock, their corresponding 15N-labeled carbodiimide and pyrimidines were readily obtained. This homogeneous-heterogeneous synergy strategy will open a new chapter for N2 transformation.

Electrophilic functionalization of N2 moieties in metal dinitrogen complexes typically initiates the catalytic synthesis of N-containing molecules directly from N2. Despite intensive research in the last six decades, how to efficiently and even quantitatively convert N2 into diazenido and hydrazido species still poses a great challenge. In this regard, systematic and comprehensive investigations to elucidate the reaction intricacies are of profound significance. Herein, we report a kinetic dissection on the first and second electrophilic functionalization steps of a new Cr0–N2 system with HOTf, MeOTf, and Me3SiOTf. All reactions pass through fleeting diazenido intermediates and furnish long-lived final hydrazido products, and both steps are quantitative conversions at low temperatures. All of the second-order reaction rates of the first and second transformations were determined as well as the lifetimes of the intervening diazenido species. Based on these findings, we succeeded in large-scale and near-quantitative preparation of all hydrazido species.