An electrochemical cell coupled with a recycle loop through a transmission FTIR cell is employed in studies of two free radical organic reactions, the oxidation of allylic alcohols and the trifluoromethylation of heteroarenes. Rapid mixing through the recycle loop allows continuous monitoring of reaction progress. Electrochemical generation of free radicals allows their controlled mediation int...

Manganese-catalyzed sequential C–H and C–C/C–Het bond activation to synthesize allylic alcohols, allylated arenes, functionalized cyclopentenes and skipped dienes is reported. This protocol can be readily scaled up and various coupling partners are applied in manganese catalysis for the first time. Moreover, manganese-catalyzed alkenyl C(sp)–H activation is also shown. Complimentary to the stan...

A fully integrated continuous process for homogeneous catalysed reactions in scCO(2) has been developed exploiting the tunable solvent properties of scCO(2). A heated condenser situated above the reaction zone leads to a phase split under isobaric conditions resulting in efficient catalyst retention and recirculation. Continuous isomerisation of allylic alcohols was carried out for over 200 hou...

The stereoselective transformation of α-alkoxyacetoaldehydes to the corresponding (Z)-vinyl triflates was achieved by treatment with phenyl triflimide and DBU. The stereochemistry was explained by the "syn-effect," which was attributed primarily to an σ → π* interaction. The β-alkoxy vinyl triflates obtained were applied to the stereoselective synthesis of structurally diverse (Z)-allylic alcoh...

Manganese-catalyzed sequential C-H and C-C/C-Het bond activation to synthesize allylic alcohols, allylated arenes, functionalized cyclopentenes and skipped dienes is reported. This protocol can be readily scaled up and various coupling partners are applied in manganese catalysis for the first time. Moreover, manganese-catalyzed alkenyl C(sp2)-H activation is also shown. Complimentary to the sta...

An oxidation of allylic and benzylic alcohols to the corresponding carboxylic acids is effected by merging a Cu-catalyzed oxidation using O2 as a terminal oxidant with a subsequent chlorite oxidation (Lindgren oxidation). The protocol was optimized to obtain pure products without chromatography or crystallization. Interception at the aldehyde stage allowed for Z/E-isomerization, thus rendering ...

A stereoselective bromocyclopropanation of allylic alcohols using dibromomethylzinc bromide is described. Spectroscopic studies to monitor the formation of transient intermediates not only led to the development of a more-atom-economical halocyclopropanation reaction, but also highlighted the unique role of ether additives in the process. The desired bromo-substituted cyclopropanes were isolate...

A highly enantioselective Rh(I)-catalyzed intramolecular Alder ene reaction has been developed. The desired products, 3-vinyl, vinyl acetate, and vinyl ether-substitued alpha-methylene-gamma-butyrolactones were formed in high yields. Aldehydes were produced with the formation of gamma-lactones when alcohols were substituted at allylic position in the substrates. All reactions with listed substr...

A direct and scalable route to γ-keto-α,β-unsaturated esters, useful intermediates in medicinal chemistry and natural products synthesis, is reported. The key step involves the use of Grubbs' second-generation olefin metathesis catalyst for cross-metathesis of alkyl acrylates and 2° allylic alcohols. The metathesis step is followed by oxidation to give the desired products in high yield on scal...

Transition-metal-free radical α-perfluoroalkylation with the accompanying vicinal β-alkenylation of unactivated alkenes is presented. These radical cascades proceed by means of 1,4- or 1,5-alkenyl migration by electron catalysis on readily accessed allylic alcohols. The reactions comprise a regioselective perfluoroalkyl radical addition with subsequent alkenyl migration and concomitant deproton...