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Abstract We have developed a novel visible‐light‐catalyzed bioconjugation reaction, PhotoCLIC, that enables chemoselective attachment of diverse aromatic amine reagents onto a site‐specifically installed 5‐hydroxytryptophan residue (5HTP) on full‐length proteins of varied complexity. The reaction uses catalytic amounts of methylene blue and blue/red light‐emitting diodes (455/650 nm) for rapid site‐specific protein bioconjugation. Characterization of the PhotoCLIC product reveals a unique structure formed likely through a singlet oxygen‐dependent modification of 5HTP. PhotoCLIC has a wide substrate scope and its compatibility with strain‐promoted azide‐alkyne click reaction, enables site‐specific dual‐labeling of a target protein.
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Tandem Diboration–Protoboration of Terminal Alkynes: A Practical Route to α-Substituted Alkenyl Boronates
Abstract A practical method is introduced for the catalytic conversion of terminal alkynes into α-substituted vinyl boronic esters. The process employs catalytic amounts of nanoparticle-supported gold catalysts and catalytic amounts of copper to effect the overall transformation.
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- Award ID(s):
- 2117246
- PAR ID:
- 10539063
- Publisher / Repository:
- SynLett
- Date Published:
- Journal Name:
- Synlett
- ISSN:
- 0936-5214
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Catalytic Halogen Exchange in Miniemulsion ARGET ATRP: A Pathway to Well‐Controlled Block CopolymersAbstract Halogen exchange in atom transfer radical polymerization (ATRP) is an efficient way to chain‐extend from a less active macroinitiator (MI) to a more active monomer. This has been previously achieved by using CuCl/L in the equimolar amount to Pn−Br MI in the chain extension step. However, this approach cannot be effectively applied in systems based on regeneration of activators (ARGET ATRP), since they operate with ppm amounts of catalysts. Herein, a catalytic halogen exchange procedure is reported using a catalytic amount of Cu in miniemulsion ARGET ATRP to chain‐extend from a less active poly(n‐butyl acrylate) (PBA) MI to a more active methyl methacrylate (MMA) monomer. Influence of different reagents on the initiation efficiency and dispersity is studied. Addition of 0.1mNaCl or tetraethylammonium chloride to ATRP of MMA initiated by methyl 2‐bromopropionate leads to high initiation efficiency and polymers with low dispersity. The optimized conditions are then employed in chain extension of PBA MI with MMA to prepare diblock and triblock copolymers.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1055/s-0043-1774906
