Pseudo High-Throughput Development and Optimization of the Electrochemical Oxidation of Sensitive Propargylic Benzylic Alco-hols

The electrochemical oxidation of sensitive propargylic benzylic alcohols having varying substituents is reported. The ther-mal oxidation of propargylic benzylic alcohols presents an acute challenge in the synthesis of complex molecules and various traditional oxidation methods proceed with low efficiency or not at all. We describe the convenient preparation and charac-terization of N-hydroxytetrafluorophthalimide (TFNHPI) and a practical, green electrochemical oxidation protocol that em-ploys TFNHPI as a stable, efficient electrochemical mediator. The electrochemical method employing TFNHPI to oxidize propargylic benzylic alcohols was developed and optimized in pseudo high-throughput fashion using a bank of inexpensive two-electrode power supplies. The electrochemical oxidation of propargylic benzylic alcohol was also leveraged to develop efficient synthetic pathways to prepare gram quantities of resveratrol natural products such as the pauciflorols.

Pd-Based Polysaccharide Hydrogels as Heterogeneous Catalysts for Oxidation of Aromatic Alcohols

Immobilization of Pd(OAc)2(TPPTS)2 in various renewable polysaccharides hydrogels, yielded heterogeneous catalysts that were successfully used, for the first time, in the aerobic oxidation of benzylic alcohol. The new catalysts were easily removed from the reaction mixture and recycled with some loss of activity. Among all tested polysaccharides, iota-carrageenan was found to be the most suitable support, using calcium chloride as a gelation agent.

Highly enantioselective access to chiral chromanes and thiochromanes via Cu-catalyzed hydroamination with anthranils

Highly efficient and atom-economic asymmetric access to 4-arylamino chromanes and thiochromanes bearing a benzylic alcohol functionality were developed by Cu(i)/(R,R)-Ph-BPE-catalyzed enantioselective hydroamination with anthranils.

Diastereoselective Total Synthesis of (+)-Raputindole A: An Iridium- Catalyzed Cyclization Approach

This work describes the total synthesis of Raputindole A <b>(1)</b> through a convergent approach which features: 1) an iridium-catalyzed cyclization to assembly the tricyclic core of the northern part, 2) enzymatic resolution to secure the preparation of enantiomerically pure benzylic alcohol, 3) installation of the butenyl substituent via methallylation of the corresponding benzylic carbocation and coupling of the northern and southern parts via Heck reaction. (+)-Raputindole A <b>(1)</b> was prepared in 10 steps (LLS) and 10% overall yield.

Diastereoselective Total Synthesis of (+)-Raputindole A: An Iridium- Catalyzed Cyclization Approach

This work describes the total synthesis of Raputindole A <b>(1)</b> through a convergent approach which features: 1) an iridium-catalyzed cyclization to assembly the tricyclic core of the northern part, 2) enzymatic resolution to secure the preparation of enantiomerically pure benzylic alcohol, 3) installation of the butenyl substituent via methallylation of the corresponding benzylic carbocation and coupling of the northern and southern parts via Heck reaction. (+)-Raputindole A <b>(1)</b> was prepared in 10 steps (LLS) and 10% overall yield.

Scandium and Dimethylaminopyridine Catalyzed Dehydrative Coupling of Secondary Benzylic and Primary Alcohols to Synthesize Unsymmetrical Ethers

We developed a direct catalytic condensation of benzylic alcohols and primary alcohols to synthesize unsymmetrical ethers in one step, catalyzed by scandium triflate and p-dimethylaminopyridine (DMAP). Preliminary experiments give some insight into the mechanism of the reaction, though suggest that the process is quite complex. We suspect the rapid formation of a dimer from a secondary benzylic alcohol via a carbocation intermediate precedes unsymmetrical ether formation. Full experimental details and spectroscopic data are provided as supplementary information.

Scandium and Dimethylaminopyridine Catalyzed Dehydrative Coupling of Secondary Benzylic and Primary Alcohols to Synthesize Unsymmetrical Ethers

We developed a direct catalytic condensation of benzylic alcohols and primary alcohols to synthesize unsymmetrical ethers in one step, catalyzed by scandium triflate and p-dimethylaminopyridine (DMAP). Preliminary experiments give some insight into the mechanism of the reaction, though suggest that the process is quite complex. We suspect the rapid formation of a dimer from a secondary benzylic alcohol via a carbocation intermediate precedes unsymmetrical ether formation. Full experimental details and spectroscopic data are provided as supplementary information.

Kraft lignin derived S and O co-doped porous graphene for metal-free benzylic alcohol oxidation

S and O co-doped graphene derived from lignin carbonization achieved 95.9% yield of benzaldehyde in metal-free oxidation of benzyl alcohol.