9 research outputs found
A Practical Chemo-enzymatic Synthesis of Homochiral Bicyclo[2.2.2]octane-2,5-dione
A practical synthetic route for the preparation of chiral bicyclo[2.2.2]octane-2,5-dione, the precursor of useful chiral diene ligands, was realized via Diels−Alder reaction and resolution of an enol acetate derivative by immobilized lipases
Rh-Catalyzed [3+2] Annulation of Cyclic Ketimines and Alkynyl Chloride: A Strategy for Accessing Unsymmetrically Substituted and Highly Functionalizable Indenes
Alkynyl chlorides
were found to be extraordinarily novel electrophiles,
which could afford a single regioisomer of the [3+2] annulation adducts
with cyclic ketimines by rhodium catalysis. The alkenyl chloride moiety
in the products provided a valuable functional handle for further
diverse transformations. Therefore, this research provided not only
a synthetic protocol for accessing unsymmetrically substituted indenyl
amines but also a highly divergent solution for decorating the substituting
group by postmanipulation of the chloride
Rh-Catalyzed [3+2] Annulation of Cyclic Ketimines and Alkynyl Chloride: A Strategy for Accessing Unsymmetrically Substituted and Highly Functionalizable Indenes
Alkynyl chlorides
were found to be extraordinarily novel electrophiles,
which could afford a single regioisomer of the [3+2] annulation adducts
with cyclic ketimines by rhodium catalysis. The alkenyl chloride moiety
in the products provided a valuable functional handle for further
diverse transformations. Therefore, this research provided not only
a synthetic protocol for accessing unsymmetrically substituted indenyl
amines but also a highly divergent solution for decorating the substituting
group by postmanipulation of the chloride
Synthesis of Zeolite EMT with Aid of Sodium Phosphate
Synthesis of Zeolite EMT with Aid of
Sodium Phosphat
Synthesis of a Bulky and Electron-Rich Derivative of SEGPhos and Its Application in Ru-Catalyzed Enantioselective Hydrogenation of β-Ketoesters
The synthesis and resolution of a bulky and electron-rich
derivative of SEGPhos and its application in Ru-catalyzed
asymmetric hydrogenation reaction of β-ketoesters are
reported. Up to 99.5% ee was achieved. Under solvent-free
reaction conditions, acetoacetates could be reduced with good
enantioselectivity and high efficiency; a TON of 20 000 was
obtained within 3.5 h. The results obtained were comparable
to those when SEGPhos was applied
DataSheet1_Porous single crystalline-like titanium dioxide monolith with enhanced photoelectrochemical performance.docx
Macro-sized porous single crystalline-like (PSC-like) TiO2 is endowed with unique structural advantages due to its structural consistency and porosity in a large area, which would significantly enhance its photoelectrochemical function. However, there are significant technical challenges in the growth of porous single crystalline-like monoliths. The consistency of structure dominates the structure so that the grain boundary is reduced to the minimum, which is in contradiction with the three-dimensional percolation structure. Here we report a lattice reconstruction strategy based on solid-solid transformation to grow porous single crystal-like anatase TiO2 dominated by (200) and (101) facets at 2 cm scale. In comparison with the traditional definition of porous single crystal, it has two different lattice orientations, but still has good photoelectrochemical properties. The band gap engineering introduces Ti3+ gap into the lattice to generate TinO2n−1 with Magneli phase, limiting the created active structure to the lattice with two-dimensional surface, which would open a new avenue to create highly active surfaces to capture photons and transport electrons stably. The PSC-like TinO2n−1 provides enhanced exciton lifetime (3–5 ns) as a photocatalytic catalyst and shows significant visible light absorption. The independent PSC-like TinO2n−1 delivers high photocurrent of 1.8–5.5 mA · cm−2 at room temperature and does not decay for 10 h.</p
Plasmonic Interference Lithography for Low-Cost Fabrication of Dense Lines with Sub-50 nm Half-Pitch
Limited by the cost
and complexity, a sub-50 nm lithography node
is hard to achieve through the traditional interference lithography.
In this paper, the dense lines with half-pitch of 32 nm (∼λ/11)
and 22 nm (∼λ/16) are first achieved at the wavelength
of 365 nm by simple plasmonic interference lithography. Through selecting
the high spatial frequency plasmonic modes in Al/Photoresist (Pr)/Al
waveguide and allowing interference with each other, the deep subwavelength
plasmonic interference field could be obtained in Pr film. Moreover,
the lithography structure is separated from the mask, so etch transfer
process from Pr to substrate after lithography is easy to attain,
and the mask with high cost could be used multiple times. Meanwhile,
a near-field lithography setup was developed, and we experimentally
realized the comparatively distinct lithography fringes with the half-pitch
of 32 and 22 nm when there is an air gap smaller than ∼20 nm
between mask and the lithography films. Compared with the imaging
lithography with 1:1 ratio, the plasmonic interference lithography
could achieve the demagnified patterns with a 2:1 ratio, which reduces
the difficulty and cost of the mask fabrication. It is believed that
this method will supply the simple and low-cost nanofabrication scenario
in the near future
Enantioselective Conjugate Addition of Aryl Halides and Triflates to Electron-Deficient Olefins via Nickel- and Rhodium-Catalyzed Sequential Relay Reactions
Asymmetric
conjugate addition of aryl halides or aryl triflates
to electron-deficient olefins was realized by sequential Miyaura borylation
and Hayashi–Miyaura conjugate addition in one pot. A nickel-catalyzed
borylation of aryl halides or triflates and a rhodium–chiral
diene complex catalyzed enantioselective conjugate addition was executed
as a pair of relay reactions as a more efficient and greener protocol