4 research outputs found
P‑Directed Borylation of Phenols
Internal borylation occurs upon activation of aryl di-isopropylphosphinite boranes with HNTf<sub>2</sub> to give heterocyclic intermediates that can be reductively quenched to afford <b>6</b> or treated with KHF<sub>2</sub> to give the phenolic potassium aryl trifluoroborate salts <b>10</b>. The latter salts are useful for Pd-catalyzed coupling with aryl iodides under Molander conditions, provided that precautions are taken to remove the KNTf<sub>2</sub> byproduct from the preceding KHF<sub>2</sub> step
P‑Directed Borylation of Phenols
Internal borylation occurs upon activation of aryl di-isopropylphosphinite boranes with HNTf<sub>2</sub> to give heterocyclic intermediates that can be reductively quenched to afford <b>6</b> or treated with KHF<sub>2</sub> to give the phenolic potassium aryl trifluoroborate salts <b>10</b>. The latter salts are useful for Pd-catalyzed coupling with aryl iodides under Molander conditions, provided that precautions are taken to remove the KNTf<sub>2</sub> byproduct from the preceding KHF<sub>2</sub> step
Selective Pinacol-Coupling Reaction using a Continuous Flow System
The first continuous flow pinacol
coupling reaction of carbonyl compounds was successfully achieved
within only 2 min during a single pass through a cartridge filled
with zinc(0). The optimized method allowed the efficient production
of gram-scale value-added compounds with high productivity. The developed
methodology is efficient for aromatic or α,β-unsaturated
aldehydes but gives moderate results for more stable acetophenone
derivatives. Moreover, the flow method displayed better results in
terms of yield and selectivity in comparison to the corresponding
batch methodology
Toward the Sustainable Synthesis of Biosourced Divinylglycol from Glycerol
Two high yielding protocols for the
dehydration of glycerol to
acrolein have been designed using strong Brönsted acid immobilized
on silica gels. Acrolein is obtained with yield ranging from 91 to
95% in organic solvent or under solvent free conditions. The optimized
solventless protocol has been then adapted for the direct formation
of divinylglycol from glycerol. Neo-formed acrolein is directly coupled
to divinylglycol by a double addition process giving 72% of the target
divinylglycol in 1 h at a 10 g scale. This process could be referred
as a two-chamber reactor with no accumulation of acrolein. Moreover,
the reaction rate can be monitored by the rate of glycerol addition,
which allows securing the whole system