A new set of stereochemically diverse phosphino-oxazoline ligands derived from simple L-amino acids and 2-(diphenylphosphaneyl)benzoic acid were developed. Those mono anionic tridentated N,N,P-ligands promote the Cu-catalyzed enantioselective radical coupling of terminal alkynes with a broad range of benzylic halides including benzo-fused cyclic α-halides and α-silyl benzyl halides in high yield and excellent enantioselectivity under mild reaction conditions. With multi distinct sites for structural modification, a diverse pool of chiral N,N,P-ligands is readily accessed, allowing for rapid optimization of the ligand structure for a specific substrate. Notably, the enantioselective alkynlylation of benzylic halides bonds in benzo-cyclic molecules has also been realized for the first time.

Despite biomass-derived methylene butyrolactone monomers having great potential in substituting the petroleumbased methacrylates for synthesizing the sustainable acrylic polymers, the possible industrial production of these cyclic monomers is unfortunately not practical due to moderate overall yields and harsh reaction conditions or a time-consuming multistep process. Here we report a convenient and effective synthetic approach to a series of biomass-derived methylene butyrolactone monomers via a zinc-mediated allylation-lactonization one-pot reaction of biorenewable aldehydes with ethyl 2-(bromomethyl)acrylate. Under simple room-temperature sonication conditions, near-quantitative conversions (>90%) can be accomplished within 5−30 min, providing pure products with high isolated yields of 70−80%. Their efficient polymerizations with a high degree of control and complete chemoselectivity were enabled by the judiciously chosen Lewis pair catalyst based on methylaluminum bis(2,6-di-tert-butyl-4-methylphenoxide) [MeAl(BHT) 2 ] Lewis acid and 3-diisopropyl-4,5-dimethylimidazol-2-ylidene (I i Pr) Lewis base, affording new poly(methylene butyrolactone)s with high thermal stability and thermal properties tuned in a wide range as well as pendant vinyl groups for postfunctionalization. Through the development of an effective depolymerization setup (370−390 °C, ca. 100 mTorr, 1 h, a muffle furnace), thermal depolymerizations of these polymers have been achieved with monomer recovery up to 99.8%, thus successfully constructing sustainable acrylic polymers with closed-loop recyclability.