Synthesis of Trifluoromethyl Ketones via Tandem Claisen Condensation and Retro-Claisen C–C Bond-Cleavage Reaction

A highly efficient, operationally simple approach to trifluoromethyl ketones has been developed that builds on the use of a tandem process involving Claisen condensation and retro-Claisen C–C bond cleavage reaction. Enolizable alkyl phenyl ketones were found to react readily with ethyl trifuoroacetate under the promotion of NaH to afford trifluoroacetic ester/ketone exchange products, trifluoromethyl ketones, which were quite different from the general Claisen condensation products, β-diketones. This procedure uses readily available starting materials and can be extended to the preparation of perfluoroalkyl ketones in excellent yield

ENO2, a Glycolytic Enzyme, Contributes to Prostate Cancer Metastasis: A Systematic Review of Literature

Prostate cancer (PCa) is the second leading cause of male cancer deaths in the UK and the fifth worldwide. The presence of distant PCa metastasis can reduce the 5-year survival rate from 100% to approximately 30%. Enolase 2 (ENO2), a crucial glycolytic enzyme in cancer metabolism, is associated with the metastasis of multiple cancers and is also used as a marker for neuroendocrine tumours. However, its role in PCa metastasis remains unclear. In this study, we systematically reviewed the current literature to determine the association between ENO2 and metastatic PCa. Medline, Web of Science, and PubMed were searched for eligible studies. The search yielded five studies assessing ENO2 expression in PCa patients or cell lines. The three human studies suggested that ENO2 expression is correlated with late-stage, aggressive PCa, including castrate-resistant PCa (CRPC), metastatic CRPC, and neuroendocrine PCa (NEPC). This was further supported by two in vitro studies indicating that ENO2 expression can be regulated by the tumour microenvironment, such as androgen deprived conditions and the presence of bone-forming osteoblasts. Therefore, ENO2 may functionally contribute to PCa metastasis, possibly due to the unique metabolic features of PCa, which are glycolysis dependent only at the advanced metastatic stage

Enantioselective Reduction of Prochiral Ketones with NaBH₄/Me₂SO₄/(<i>S</i>)-Me-CBS

<div><p></p><p>The enantioselective reduction of prochiral ketones with NaBH₄/Me₂SO₄/(<i>S</i>)-Me-CBS is described. Borane is generated in situ via the reaction of NaBH₄ with Me₂SO₄ in tetrahydrofuran, which is as efficient as the commercial one. Such in situ–generated borane reagent was applied to reduce prochiral ketones in the presence of chiral oxazaborolidine catalyst directly. The corresponding chiral secondary alcohols were obtained with excellent enantiomeric excesses (93–99% <i>ee</i>) and good to excellent yield (80–99%).</p> </div

Synthesis of <i>gem</i>-Difluoroallylboronates via FeCl₂‑Catalyzed Boration/β-Fluorine Elimination of Trifluoromethyl Alkenes

The first ferrous chloride catalyzed boration/β-fluorine elimination of trifluoromethyl alkenes is described. Thus, a full range of <i>gem</i>-difluoroallylboronates were obtained in high yield under mild conditions. As an important fluorinated building block, <i>gem</i>-difluoroallylboronate can be readily converted into diverse difluoro-substituted species

Catalytic Asymmetric Synthesis of Esomeprazole by a Titanium Complex with a Hexa-aza-triphenolic Macrocycle Ligand

<div><p></p><p>An efficient synthesis of esomeprazole via catalytic asymmetric oxidation of 1<i>H</i>-benzimidazolyl pyridinylmethyl sulfide by a titanium complex with a hexa-aza-triphenolic macrocycle ligand is described. Esomeprazole was prepared with 99.6% <i>ee</i>, which meets the high requirement of the European Pharmacopeia on enantiomeric purity.</p> </div

Highly Enantio- and Diastereoselective Vinylogous Aldol Reaction by LiCl-Assisted BINOL–Titanium Species

The first highly enantio- and diastereoselective vinylogous aldol reaction between propionyl acetate-derived Brassard’s diene and aldehydes was accomplished by titanium–lithium combined Lewis acid, affording δ-hydroxy-γ-methyl-β-methoxy acrylates. This methodology was utilized in convenient and concise construction of the polypropionate moiety in cystothiazole A and melithiazole C

Iron-catalyzed boration of allylic alcohols with H₃BO₃ as an additive

<p>A method for the synthesis of allylboronates by iron-catalyzed boration of allylic alcohols with H₃BO₃ as an additive is developed. The introduction of H₃BO₃ promotes the cleavage of C‒O bond in allylic alcohols obviously. Functional groups, such as fluoro, chloro, bromo, alkyl, and alkoxy, are tolerated well. Thus, various allylboronates are obtained in acceptable yield.</p

Synthesis of (<i>Z</i>)‑α-Trifluoromethyl Alkenyl Triflate: A Scaffold for Diverse Trifluoromethylated Species

An efficient method for the synthesis of (<i>Z</i>)-selective α-trifluoromethyl alkenyl triflates is described. As an important fluorinated building block, it is utilized successfully for the synthesis of various trifluoromethyl derivatives such as diarylethylenes, enynes, alkynes, and benzofurans

Synthesis of (<i>Z</i>)‑α-Trifluoromethyl Alkenyl Triflate: A Scaffold for Diverse Trifluoromethylated Species

An efficient method for the synthesis of (<i>Z</i>)-selective α-trifluoromethyl alkenyl triflates is described. As an important fluorinated building block, it is utilized successfully for the synthesis of various trifluoromethyl derivatives such as diarylethylenes, enynes, alkynes, and benzofurans

Base-Controlled Regiodivergent Azidation of Trifluoromethyl Alkenyl Triflates: Transition-Metal-Free Access to CF₃‑Containing Allyl Azides and Alkenyl Azides

A base-controlled regiodivergent azidation of trifluoromethyl alkenyl triflates providing either (<i>E</i>)-3-azido-1-aryl-4,4,4-trifluorobut-1-ene (CF₃-containing allyl azides) or (<i>Z</i>)-1-azido-1-aryl-4,4,4-trifluorobut-1-ene (CF₃-containing alkenyl azides) is described. Catalyzed by Et₃N, the azidation of trifluoromethyl alkenyl triflates with TMSN₃ gave CF₃-containing allyl azides. On the other hand, using stoichiometric DBU, the regioisomeric azidation products, CF₃-containing alkenyl azides, were obtained in good yield. A further transformation for CF₃-containing amines, triazoles, and azirines highlights the practical applicability of this transition-metal-free protocol