Fast Ring-Opening Metathesis Polymerization of Tricyclic Oxanorbornene Derivatives

A new type of tricyclic oxanorbornene monomer was developed for living ring-opening metathesis polymerization (ROMP). A methyl group located at the endoposition of the oxanorbornene bicycle resulted in polymerization kinetics orders of magnitude slower than the corresponding hydrogen-substituted monomers because of steric effects. Both monomers showed well-controlled molecular weights and excellent dispersities with Grubbs’ third-generation catalyst. The slower endomethyl substituted monomers could even be polymerized in a well-controlled manner using Grubbs’ second-generation catalyst. Investigations of random copolymers demonstrated that the steric hindrance only affects the rate of propagation rather than the rate of initiation. Block copolymers between the fast and slow monomers could be prepared with good molecular weight and dispersity control

Asymmetric Synthesis of α‑Trifluoromethyl Pyrrolidines through Organocatalyzed 1,3-Dipolar Cycloaddition Reaction

The optically active α-trifluoromethyl pyrrolidines have been achieved through organocatalyzed 1,3-dipolar cycloaddition reaction first. With diphenylprolinol trimethylsilyl ether as catalyst and in the presence of 3,5-dinitrobenzoic acid, the reaction of trifluoro­ethyl­amine-derived ketimine with 2-enals gave α-trifluoromethyl pyrrolidines bearing three contiguous stereogenic centers in excellent diastereoselectivies, stereoselectivities, and yields

Asymmetric Synthesis of α‑Trifluoromethyl Pyrrolidines through Organocatalyzed 1,3-Dipolar Cycloaddition Reaction

The optically active α-trifluoromethyl pyrrolidines have been achieved through organocatalyzed 1,3-dipolar cycloaddition reaction first. With diphenylprolinol trimethylsilyl ether as catalyst and in the presence of 3,5-dinitrobenzoic acid, the reaction of trifluoro­ethyl­amine-derived ketimine with 2-enals gave α-trifluoromethyl pyrrolidines bearing three contiguous stereogenic centers in excellent diastereoselectivies, stereoselectivities, and yields

Table_1_Advances in the relationship between temporal muscle thickness and prognosis of patients with glioblastoma: a narrative review.docx

The most dangerous variety of glioma, glioblastoma, has a high incidence and fatality rate. The prognosis for patients is still bleak despite numerous improvements in treatment approaches. We urgently need to develop clinical parameters that can evaluate patients' conditions and predict their prognosis. Various parameters are available to assess the patient's preoperative performance status and degree of frailty, but most of these parameters are subjective and therefore subject to interobserver variability. Sarcopenia can be used as an objective metric to measure a patient's physical status because studies have shown that it is linked to a bad prognosis in those with cancers. For the purpose of identifying sarcopenia, temporal muscle thickness has demonstrated to be a reliable alternative for a marker of skeletal muscle content. As a result, patients with glioblastoma may use temporal muscle thickness as a potential marker to correlate with the course and fate of their disease. This narrative review highlights and defines the viability of using temporal muscle thickness as an independent predictor of survival in glioblastoma patients, and it evaluates recent research findings on the association between temporal muscle thickness and prognosis of glioblastoma patients.</p

The Regiocontrollable Enantioselective Synthesis of Chiral Trifluoromethyl-Containing Spiro-Pyrrolidine-Pyrazolone Compounds via Amino-Regulated 1,3-Proton Migration Reaction

An amino-controlled regiodivergent asymmetric synthesis of CF3-containing spiro-pyrrolidine-pyrazolone compounds is described. With alkaloid-derived squaramide as catalyst, the 1,3-dipolar cycloaddition of α,β-unsaturated pyrazolone with diethyl 2-((2,2,2-trifluoroethyl)­imino) malonate offered adducts in excellent yields, dr, and ee. While the cyclohexanediamine-derived squaramide was employed, the reaction afforded a series of structure isomers through a switched umpolung reaction

Synthesis of Chiral α‑Trifluoro­methyl­amines with 2,2,2-Trifluoro­ethylamine as a “Building Block”

The β-isocupreidine, a cinchonine derived alkaloid, catalyzed asymmetric SN2′–SN2′ reaction between N-2,2,2-trifluoroethylisatin ketimines and MBH type carbonates was realized in a simple and efficient way. A series of chiral α-trifluoromethylamines were prepared with excellent yields and stereoselectivities. A subsequent and easy process of deprotection gave γ-trifluoromethyl-α-methylene­lactam in a stereoselective manner

Synthesis of Chiral α‑Trifluoro­methyl­amines with 2,2,2-Trifluoro­ethylamine as a “Building Block”

The β-isocupreidine, a <i>cinchonine</i> derived alkaloid, catalyzed asymmetric S_N2′–S_N2′ reaction between <i>N</i>-2,2,2-trifluoroethylisatin ketimines and MBH type carbonates was realized in a simple and efficient way. A series of chiral α-trifluoromethylamines were prepared with excellent yields and stereoselectivities. A subsequent and easy process of deprotection gave γ-trifluoromethyl-α-methylene­lactam in a stereoselective manner

Asymmetric Synthesis of CF₃- and Indole-Containing Thiochromanes via a Squaramide-Catalyzed Michael–Aldol Reaction

A Michael–aldol reaction of 2-mercaptobenzaldehyde with β-indole-β-CF₃ enones catalyzed by a squaramide has been realized. The method affords a series of 2-CF₃-2-indole-substituted thiochromanes featuring a CF₃-containing quaternary stereocenter in excellent yields, diastereoselectivities, and enantioselectivities