Synthesis and cross coupling of a highly substituted 2-pyridylboronate: application to the large scale synthesis of a mineralocorticoid antagonist

The large scale synthesis of functionalized 2-pyridylboronate 8 and optimization of its Suzuki-Miyaura coupling to chloropyrazoline (R)-7 to provide a scalable synthesis of mineralocorticoid antagonist (R)-1 is described.     

Plasmonic modes of nanobox,nanocage, and nanoframe

The scattering, absorption, and extinction cross sections of Ag nanobox, nanocage, and nanoframe illuminated by a polarized plane wave are studied using the finite element method. Our numerical results show that the plasmon modes (dipole and quadrupole modes) of a single Ag nanocage are red-shifted as the thickness of the wall decreases. In addition, the plasmon modes of porous nanocage and nanoframe are red-shifted relative to the nanobox as the surface porosity of nanocage increases. In particular, the wavelengths at the peaks of these modes almost linearly depend on the surface porosity. Moreover, the scattering efficiency of the dipole mode is much higher than the absorption one. The former is broadband, while the latter narrowband. These modes are confirmed by their far-field scattering patterns, and the corresponding surface electric field distributions are also investigated.     

Investigation of the asymmetric Birch reduction-alkylation of a chiral 5-arylbenzamide containing a carbamate group

The synthesis and asymmetric Birch reduction-alkylation of chiral benzamide 17 are described. Birch reductive alkylation of benzamide 17 was optimized to give the corresponding cyclohexa-1,4-diene products in 66-78% isolated yield and with high diastereoselectivity (dr: >98:2). The effects of performing the reduction in the presence and in the absence of tert-butyl alcohol are discussed.     

Optimization of a Pd-catalyzed intramolecular α-arylation synthesis of tricyclo-[7.3.1.0]-trideca-2,4,6-trien-13-ones

We have optimized the Pd-catalyzed intramolecular α-arylation of 2-(2-halo-benzyl)-cyclohexanones and found that the use of 2-(dicyclohexylphosphino)-2′,4′,6′-tri-i-propyl-1,1′-biphenyl (X-Phos) as an added ligand led to a reproducible, efficient, and scalable synthesis of tricycle-[7.3.1.0^2,7]-trideca-2,4,6-trien-13-ones.