Reversing the conventional site-selectivity of CÀ H activation processes provides new retrosynthetic disconnections to otherwise unreactive bonds. Here, we report a new catalytic system based on palladium/ norbornene and an S,O-ligand for the meta-CÀ H arylation of aryl ethers that significantly outperforms previously reported systems. We demonstrate the unique ability of this system to employ alkoxyarene substrates bearing electron donating and withdrawing substituents. Additionally, ortho-substituted aryl ethers are well tolerated, overcoming the "ortho constraint", which is the necessity to have a meta-substituent on the alkoxyarene to achieve high reaction efficiency, by enlisting novel norbornene mediators. Remarkably, for the first time the monoarylation of alkoxyarenes is achieved efficiently enabling the subsequent introduction of a second, different aryl coupling partner to rapidly furnish unsymmetrical terphenyls. Further insight into the reaction mechanism was achieved by isolation and characterization of some Pd-complexesbefore and after meta CÀ H activation-prior to evaluation of their respective catalytic activities.

A catalytic enantioselective aza-Reformatsky reaction with cyclic dibenzo[b,f][1,4]oxazepines and ethyl iodoacetate is reported.

The diastereoselective synthesis of highly substituted β-lactams by intramolecular Tsuji–Trost allylation is reported. Judicious selection of the ligand on palladium allows selective access to either the trans isomer (in generally good to excellent yield with very high diastereomeric excess) or cis isomer (with yields and diastereoselectivity ranging from modest to excellent depending on the substrate). The reaction proceeds under exceedingly mild conditions (rt, no additives) with a broad range of substrates, which are readily accessible by the Ugi reaction.

The C−H olefination of substituted anisole derivatives by a Pd/S,O‐ligand catalyst is reported. The reaction proceeds under mild conditions with a broad range of substituted aryl ethers bearing both electron donating and withdrawing substituents at ortho, meta and para positions. Aryl ethers are used as limiting reagents and good yields and site selectivities are observed. The methodology is operationally simple and can be performed under aerobic conditions.

Various substituted dibenzo[b,f][1,4]oxazepines underwent an enantioselective alkylation with Et2Zn catalyzed by a (R)-VAPOL-Zn(II) complex. The corresponding chiral 11-ethyl-10,11dihydrodibenzo[b,f][1,4]oxazepine derivatives were obtained with good yields and moderate enantioselectivities. This represents the first example of enantioselective addition of Et2Zn to cyclic aldimines.