Synthesis of Oxygenated ortho-Methylbenzaldehydes via Aryne [2+2] Cycloaddition and Benzocyclobutenol Ring Opening

Herein, a two-step procedure for the preparation of oxygenated ortho-methylbenzaldehyde derivatives, starting from commercially available bromoarenes, is described. The synthesis features the simultaneous and highly regioselective installation of both the methyl and the formyl group onto the benzene core via benzyne [2+2] cycloadditions with acetaldehyde lithium enolate to give the corresponding benzocyclobutenols in high yields. Bond-selective ring opening of the benzocyclobutenols under basic conditions in methanol delivers the title compounds

Enantioselective intramolecular (2+2)-photocycloaddition reactions of 4-substituted quinolones catalyzed by a chiral sensitizer with a hydrogen-bonding motif

Six 2-quinolones, which bear a terminal alkene linked by a three- or four-membered tether to carbon atom C4 of the quinolone, were synthesized and subjected to an intramolecular [2 + 2]-photocycloaddition. The reaction delivered the respective products in high yields (78-99%) and with good regioselectivity in favor of the straight isomer. If conducted in the presence of a chiral hydrogen-bonding template (2.5 equiv) at low temperature in toluene as the solvent, the reaction proceeded enantioselectively (83-94% ee). An organocatalytic reaction was achieved when employing a chiral hydrogen-bonding template with an attached sensitizing unit (benzophenone or xanthone). The xanthone-based organocatalyst proved to be superior as compared to the respective benzophenone. Closer inspection revealed that the reaction of 4-(pent-4-enyloxy)quinolone leading to a six-membered ring, annelated to the cyclobutane, was less enantioselective (up to 41% ee with 30 mol % catalyst) than the reaction of 4-(but-3-enyloxy)quinolone leading to a five-membered ring (90% ee with 5 mol % and 94% ee with 20 mol % catalyst). Photophysical data (emission spectra, laser flash photolysis experiments) proved that the latter photocycloaddition was significantly faster, supporting the idea that the dissociation of the substrate from the catalyst prior to the photocycloaddition is responsible for the decreased enantioselectivity. Under optimized conditions, employing 10 mol % of the xanthone-based organocatalyst at -25 degrees C in trifluorotoluene as the solvent, three of the other four substrates gave the intramolecular [2 + 2]-photocycloaddition products with high enantioselectivities (72-87% ee). In all catalyzed reactions, the yields based on conversion were moderate to good (40-93%).This work was supported by the Deutsche Forschungsgemeinschaft (DFG) in Germany (Schwerpunktprogramm Organokatalyse and Graduiertenkolleg GRK 1626 Chemical Photocatalyis). Financial support from the Spanish Government is also acknowledged (JAE-doc fellowship for M.C.C. and CTQ2009-13699).Müler, C.; Bauer, A.; Maturi, MM.; Cuquerella Alabort, MC.; Miranda Alonso, MÁ.; Bach, T. (2011). Enantioselective intramolecular (2+2)-photocycloaddition reactions of 4-substituted quinolones catalyzed by a chiral sensitizer with a hydrogen-bonding motif. Journal of the American Chemical Society. 133:16689-16697. doi:10.1021/ja207480qS166891669713

The BUFFALO HST Survey

The Beyond Ultra-deep Frontier Fields and Legacy Observations (BUFFALO) is a 101 orbit + 101 parallel Cycle 25 Hubble Space Telescope (HST) Treasury program taking data from 2018 to 2020. BUFFALO will expand existing coverage of the Hubble Frontier Fields (HFF) in Wide Field Camera 3/IR F105W, F125W, and F160W and Advanced Camera for Surveys/WFC F606W and F814W around each of the six HFF clusters and flanking fields. This additional area has not been observed by HST but is already covered by deep multiwavelength data sets, including Spitzer and Chandra. As with the original HFF program, BUFFALO is designed to take advantage of gravitational lensing from massive clusters to simultaneously find high-redshift galaxies that would otherwise lie below HST detection limits and model foreground clusters to study the properties of dark matter and galaxy assembly. The expanded area will provide the first opportunity to study both cosmic variance at high redshift and galaxy assembly in the outskirts of the large HFF clusters. Five additional orbits are reserved for transient followup. BUFFALO data including mosaics, value-added catalogs, and cluster mass distribution models will be released via MAST on a regular basis as the observations and analysis are completed for the six individual clusters

Efficacy, durability, and safety of intravitreal faricimab up to every 16 weeks for neovascular age-related macular degeneration (TENAYA and LUCERNE): two randomised, double-masked, phase 3, non-inferiority trials

Background: Faricimab is a bispecific antibody that acts through dual inhibition of both angiopoietin-2 and vascular endothelial growth factor A. We report primary results of two phase 3 trials evaluating intravitreal faricimab with extension up to every 16 weeks for neovascular age-related macular degeneration (nAMD). Methods: TENAYA and LUCERNE were randomised, double-masked, non-inferiority trials across 271 sites worldwide. Treatment-naive patients with nAMD aged 50 years or older were randomly assigned (1:1) to intravitreal faricimab 6·0 mg up to every 16 weeks, based on protocol-defined disease activity assessments at weeks 20 and 24, or aflibercept 2·0 mg every 8 weeks. Randomisation was performed through an interactive voice or web-based response system using a stratified permuted block randomisation method. Patients, investigators, those assessing outcomes, and the funder were masked to group assignments. The primary endpoint was mean change in best-corrected visual acuity (BCVA) from baseline averaged over weeks 40, 44, and 48 (prespecified non-inferiority margin of four letters), in the intention-to-treat population. Safety analyses included patients who received at least one dose of study treatment. These trials are registered with ClinicalTrials.gov (TENAYA NCT03823287 and LUCERNE NCT03823300). Findings: Across the two trials, 1329 patients were randomly assigned between Feb 19 and Nov 19, 2019 (TENAYA n=334 faricimab and n=337 aflibercept), and between March 11 and Nov 1, 2019 (LUCERNE n=331 faricimab and n=327 aflibercept). BCVA change from baseline with faricimab was non-inferior to aflibercept in both TENAYA (adjusted mean change 5·8 letters [95% CI 4·6 to 7·1] and 5·1 letters [3·9 to 6·4]; treatment difference 0·7 letters [-1·1 to 2·5]) and LUCERNE (6·6 letters [5·3 to 7·8] and 6·6 letters [5·3 to 7·8]; treatment difference 0·0 letters [-1·7 to 1·8]). Rates of ocular adverse events were comparable between faricimab and aflibercept (TENAYA n=121 [36·3%] vs n=128 [38·1%], and LUCERNE n=133 [40·2%] vs n=118 [36·2%]). Interpretation: Visual benefits with faricimab given at up to 16-week intervals demonstrates its potential to meaningfully extend the time between treatments with sustained efficacy, thereby reducing treatment burden in patients with nAMD