Ring-Opening Metathesis Polymerization of Levoglucosenone-Derived Enyne Monomers.

Levoglucosenone () has emerged as a versatile synthon in target-oriented synthesis due to its availability from cellulose. While its functionality and chirality have found direct use as a small molecule building block, translation to polymerization has been more challenging. Monomers derived from have been difficult to polymerize through conventional chain-growth approaches due to lack of ring strain and steric hindrance.

Highly efficient Ca chelation activated by visible light.

Calcium ion (Ca) control is an essential tool in neuronal research. Herein, we report three thiocoumarin-based, visible light-activated Ca chelators with quantum yields of 0.39, 0.

Alternating Cascade Metathesis Polymerization of Enynes and Cyclic Enol Ethers with Active Ruthenium Fischer Carbenes.

Ruthenium alkoxymethylidene complexes have rarely been demonstrated as active species in metathesis reactions and are frequently regarded as inert. Herein, we highlight the ability of these Fischer-type carbenes to participate in cascade alternating ring-opening metathesis polymerization through their efficient alkyne addition reactions. When enyne monomers are combined with low-strain cyclic vinyl ethers, a controlled chain-growth copolymerization occurs that exhibits high degrees of alternation (>90% alternating diads) and produces degradable poly(vinyl ether) materials with low dispersities and targetable molecular weights.