Divergent and Stereoselective Synthesis of Tetraarylethylenes from Vinylboronates

Hindered Tetraphenylethylene Helicates: Chiral Fluorophores with Deep-Blue Emission, Multiple-Color CPL, and Chiral Recognition Ability

New hindered tetraphenylethylene (TPE) helicates with substitution at 2,6-position of phenyl rings were designed and synthesized. Due to the increased hindrance, the TPE helicates emit strong deep-blue to violet fluorescence both in the solid state and in solution, and could be resolved into enantiomers that emit strong and multicolor circularly polarized luminescence (CPL), and exhibit a high enantioselective recognition of chiral tartaric acid and its derivatives. Surprisingly, the derived helicate tetramines possess amino groups with an unpredented planar structure and sp² -hybridized nitrogen, arousing the change between AIE effect and ACQ phenomenon through photoinduced electron transfer (PET). With advantages of short synthetic route, many modification positions, deep-blue to violet emission, wide CPL tuning, and high chiral recognition ability, the hindered TPE helicates show broad prospects as chiral materials.

Regio- and Stereoselective 1,2-Carboboration of Ynamides with Aryldichloroboranes

Catalyst‐free 1,2‐carboboration of ynamides is presented. Readily available aryldichloroboranes react with alkyl‐ or aryl‐substituted ynamides in high yields with complete regio‐ and stereoselectivity to valuable β‐boryl‐β‐alkyl/aryl α‐aryl substituted enamides which belong to the class of trisubstituted alkenylboronates. The 1,2‐carboboration reaction is experimentally easy to conduct, shows high functional group tolerance and broad substrate scope. Gram‐scale reactions and diverse synthetic transformations convincingly demonstrate the synthetic potential of this method. The reaction can also be used to access 1‐boraphenalenes, a class of boron‐doped polycyclic aromatic hydrocarbons.

A New Kind of RIV-type AIEgens and Their Applications for the Construction of Multifunctional Luminescent MOFs

In this work, a new kind of butterfly-like molecules of oxacalix[2]arene[2]pyrazine (OAP) are reported, which exhibit typical characteristics of aggregation-induced emission (AIE) via the restriction of intramolecular vibration (RIV) mechanism. Unlike any of the reported RIV-type AIE molecules, the synthetic procedures of which are complicated and associated high costs, OAP AIEgens can be synthesized in a facile manner by a one-step catalyst-free reaction using commercially available materials. Notably, OAP AIEgens are ideal ligands for constructing metal-organic frameworks (MOFs) due to their built-in coordination sites of pyrazine groups. OAP-based MOFs exhibit multiple potential applications in reversible gas response, encrypted information storage, and construction of white light-emitting devices. This work enriches limited kinds of RIV-type AIEgens, offers additional selections of bridging ligands for constructing luminescent MOFs and provides a visualized prototype to understand the effect of RIV process on the luminescence property of MOFs.