Pd 0 -catalyzed Mizoroki-Heckr eactions traditionally exhibit poor reactivity with polysubstituted, unbiased alkenes.I ntermolecular reactions with simple,a ll-carbon tetrasubstituted alkenes are unprecedented. Herein we report that pendant carboxylic acids,c ombined with bulky monophospine ligands on palladium, can direct the arylation of triand tetrasubstituted olefins.Q uaternary carbons are established at high Fsp 3 attached-ring junctures and the carboxylate directing group can be removed after coupling.C arboxylate directivity prevents over-arylation of the new,l ess substituted alkene,which can be diversified in subsequent reactions.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Pd0‐catalyzed Mizoroki–Heck reactions traditionally exhibit poor reactivity with polysubstituted, unbiased alkenes. Intermolecular reactions with simple, all‐carbon tetrasubstituted alkenes are unprecedented. Herein we report that pendant carboxylic acids, combined with bulky monophospine ligands on palladium, can direct the arylation of tri‐ and tetrasubstituted olefins. Quaternary carbons are established at high Fsp3 attached‐ring junctures and the carboxylate directing group can be removed after coupling. Carboxylate directivity prevents over‐arylation of the new, less substituted alkene, which can be diversified in subsequent reactions.

The stereospecific ionic ring‐opening polymerization of various donor‐acceptor cyclopropanes is reported. The chiral cyclopropane monomers are readily prepared with established methodology and stereospecific polymerization is best conducted with a catalytic amount of MgBr2 serving as a Lewis acid and as an initiator. Polymers with molecular masses of up to 7800 g mol−1 containing a stereocenter in every repeating unit are obtained and the substituents of the monomers can be readily varied to access a novel class of chiral polymers.

<div><div><div><p>Pd(0)-catalyzed, non-chain-walking Mizoroki-Heck reactions exhibit poor reactivity with polysubsti- tuted, unbiased alkenes. Intermolecular reactions with simple, all-carbon tetrasubstituted alkenes are unprecedented. Here we report that pendant carboxylic acids, combined with bulky monophospine ligands on palladium, can direct the arylation of tri- and tetrasubstituted olefins. Quaternary carbons are established at high Fsp3 attached-ring junctures and the carboxylate directing group can be removed after coupling. Carboxylate directivity prevents over-arylation of the new, less hindered alkene, which can be diversified in subsequent reactions.</p></div></div></div>

<div><div><div><p>Pd(0)-catalyzed, non-chain-walking Mizoroki-Heck reactions exhibit poor reactivity with polysubsti- tuted, unbiased alkenes. Intermolecular reactions with simple, all-carbon tetrasubstituted alkenes are unprecedented. Here we report that pendant carboxylic acids, combined with bulky monophospine ligands on palladium, can direct the arylation of tri- and tetrasubstituted olefins. Quaternary carbons are established at high Fsp3 attached-ring junctures and the carboxylate directing group can be removed after coupling. Carboxylate directivity prevents over-arylation of the new, less hindered alkene, which can be diversified in subsequent reactions.</p></div></div></div>