An efficient Co-catalyzed 1,4-addition reaction of alkyl/aryl triflates and tosylates with activated alkenes is described. In this reaction, air-stable cobalt(II) complex, mild reducing agent Zn and simple proton source (H2O) are used. A radical mechanism for the addition of alkyl tosylates to activated alkenes is likely involved.
New polymer materials for contact lens applications
申请人:CIS Pharma AG
公开号:US20200283560A1
公开(公告)日:2020-09-10
The present invention relates to copolymers made from a polymerization mixture comprising (a) one or more polymerizable monomers, which monomers are characterized as having at least one vinylic group and not containing an amino acid residue, (b) one or more not-functionalized side chain-linked amino acids, (c) one or more functionalized side chain-linked amino acids, (d) a free radical initiator and, optionally, (e) a chain-transfer-agent. It also relates to block copolymers comprising the same monomers. The invention also encompasses silicone hydrogel contact lenses coated with or comprising the latter copolymers and block copolymers as well methods for introducing the copolymers and block copolymers into silicone hydrogel contact lenses.
Insertion of unsaturated systems such as alkynes and olefins into unactivated sp3 CH bonds remains an unexplored problem. We herein address this issue by successfully incorporating a wide variety of functionalized alkynes and electron‐deficient olefins into the unactivated sp3 CH bond of pivalic acid derivatives with excellent syn‐ and linear‐ selectivity. A strongly chelating 8‐aminoquinoline directing
An efficient method for the direct introduction of alkoxy groups into the β-position of alkene moieties of various α,β-unsaturatedcarbonylcompounds through the palladium-catalyzed C(sp2)–H monoalkoxylation using alcohols in the presence of sodium nitrite was developed; the corresponding enol ethers were selectively synthesized with minimal generation of acetals.