Photochemical Nickel-Catalyzed Reductive Migratory Cross-Coupling of Alkyl Bromides with Aryl Bromides

A novel method to access 1,1-diarylalkanes from readily available, nonactivated alkyl bromides and aryl bromides via visible-light-driven nickel and iridium dual catalysis, wherein diisopropylamine (^<i>i</i>Pr₂NH) is used as the terminal stoichiometric reductant, is reported. Both primary and secondary alkyl bromides can be successfully transformed into the migratory benzylic arylation products with good selectivity. Additionally, this method showcases tolerance toward a wide array of functional groups and the presence of bases

Nickel-Catalyzed Regio- and Enantioselective Borylative Coupling of Terminal Alkenes with Alkyl Halides Enabled by an Anionic Bisoxazoline Ligand

Chiral boronic esters are a class of versatile building blocks. We describe herein an asymmetric nickel-catalyzed borylative coupling of terminal alkenes with nonactivated alkyl halides. The success of this asymmetric reaction is ascribed to the application of a chiral anionic bisoxazoline ligand. This study provides a three-component strategy to access α- and β-stereogenic boronic esters from easily accessible starting materials. This protocol is characterized by mild reaction conditions, wide substrate scope and high regio- and enantioselectivity. We also showcase the value of this method in simplifying the synthesis of several drug molecules. Mechanistic studies suggest that the generation of enantioenriched boronic esters bearing an α-stereogenic center results from a stereoconvergent process, while the enantioselectivity-controlling step in the generation of boronic esters with a β-stereocenter is switched to the olefin migratory insertion step due to coordination of an ester group

Efficient Synthesis and PISA Behavior of Molecular Bottlebrush Block Copolymers via a Grafting-From Strategy through RAFT Dispersion Polymerization

Precise synthesis of molecular bottlebrushes (MBBs) with high yield via the grafting-from strategy using a reversible deactivation radical polymerization (RDRP) technique has remained elusive. Herein, the molecular bottlebrush block copolymers (MBB BCPs) with high yield and varying chemical compositions were synthesized via a polymerization-induced self-assembly (PISA)-assisted grafting-from strategy by reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization. First, the poly(norbornene-g-poly(ethylene oxide))-b-poly(norbornene-g-chain transfer agent) [P(NB-g-PEG45)-b-P(NB-CTA)] BCPs with varied chemical compositions were synthesized by sequential ring-opening metathesis polymerization (ROMP) of norbornene PEG macromonomers (NB-PEG45) and norbornene chain transfer agent (NB-CTA) monomers. Subsequently, these P(NB-g-PEG45)m-b-P(NB-CTA)n BCPs were used as multifunctional macro-CTAs for the synthesis of MBB BCPs with a high yield (up to 80% styrene monomer conversion) and a low dispersity (Đ < 1.15) via a grafting-from strategy through RAFT dispersion polymerization. The PISA behaviors of these MBB BCPs were also investigated, and the results indicated that the MBB BCPs assemblies were transformed from spherical micelles into two-dimensional disk-like micelles because the rigidity of the PS MBB segment increased with the growth of PS side chains

Efficient Metal-Free Norbornadiene–Maleimide Click Reaction for the Formation of Molecular Bottlebrushes

A highly efficient metal-free grafting-onto strategy based on the cyclopentadiene (Cp)–maleimide click reaction was developed for the preparation of molecular bottlebrushes (MBBs) with diverse morphologies and compositions. First, the masked Cp units, norbornadiene (NBD) groups, were introduced onto poly­(2-hydroxyethyl acrylate) (PHEA) as repeated anchoring groups to produce the PHEA–NBD backbone-to-be with different degrees of polymerization (DPs). Meanwhile, maleimide-terminated polyethylene glycol, poly­(tert-butyl acrylate), poly­(N,N-dimethylacrylamide), and poly­(N,N-dimethylaminoethyl acrylate) were synthesized as side chains (SCs). Subsequently, the metal-free NBD–Mal click reaction under mild conditions was applied for preparing the MBBs with a tunable morphology and various functionalities. The grafting density was affected by the concentration and composition of the SCs. When the concentration of the SC was 0.06 M, the grafting density can reach up to 92% at the feed ratio of [Mal]/[NBD] = 1:1 and increase to 100% at the feed ratio of [Mal]/[NBD] = 1.5:1. Atomic force microscopy characterization indicated that the morphology of the obtained MBBs could be tuned from rodlike to wormlike by variation of the DP of the backbone from 105 to 419

High-Yield Synthesis of Molecular Bottlebrushes via PISA-Assisted Grafting-from Strategy

To prepare molecular bottlebrushes with high yield via a grafting-from strategy using a reversible deactivation radical polymerization (RDRP) technique has always been a big challenge due to the intra- and intermolecular radical–radical coupling. Herein, a polymerization-induced self-assembly (PISA)-assisted grafting-from strategy based on reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization was developed to synthesize the Janus molecular bottlebrushes with a well-defined structure and high yield using polynorbornene-g-(poly­(ethylene glycols)-branch-RAFT agent) (PNB-g-(PEG-branch-CTA)) as a solvophilic multifunctional macro-CTA. The results indicated the biradical coupling terminations of propagating side chains could be significantly suppressed due to the nanoconfinement effect in the PISA of the generated Janus molecular bottlebrushes. Janus molecular bottlebrushes with a narrow molecular weight distribution (Mw/Mn < 1.25) and negligible intermolecular cross-linking at monomer conversion as high as 84% were prepared, demonstrating the efficiency and versatility of the PISA-assisted grafting-from approach

Supplementary Table S4 from Estrogen Receptor Alpha Mutations in Breast Cancer Cells Cause Gene Expression Changes through Constant Activity and Secondary Effects

Table S4. Multi-study ER mutation associated gene expression changes.</p

Supplementary Table S2 from Estrogen Receptor Alpha Mutations in Breast Cancer Cells Cause Gene Expression Changes through Constant Activity and Secondary Effects

Table S2. Mutant-specific up- and down-regulated genes.</p

Unprocessed data for MTS assay.

(XLSX)</p

Densitometry for yeast cycloheximide chase experiments.

(XLSX)</p

Supplementary Figures, Experimental Details, and Tables S1, S3, S5 and S6 from Estrogen Receptor Alpha Mutations in Breast Cancer Cells Cause Gene Expression Changes through Constant Activity and Secondary Effects

Supplementary Figures, Experimental Details, and Tables S1, S3, S5 and S6</p