Bleaching Earths as Powerful Additives for Ru-Catalyzed Self-Metathesis of Non-Refined Methyl Oleate at Pilot Scale.

A practical and cost-effective ruthenium-catalyzed self-metathesis of non-refined methyl oleate (85 %) derived from very high oleic sunflower oils was demonstrated at pilot scale using a robust and kg-scale commercially available SIPr-M71 pre-catalyst. The simple addition of 1 wt % bleaching earths (Tonsil 110FF) to a thermally pretreated oil could efficiently prevent catalyst deactivation. Remarkably, without the need for filtration, the catalytic system was able to achieve a turnover number (TON) of more than 744 000 at a catalyst loading of only 1 ppm. At large scale (up to 200 kg), the equilibrium of the self-metathesis reaction was reached within 1 hour at 50 °C under neat conditions at a very low 5 ppm catalyst loading to produce the expected primary metathesis products (PMP), that is, 9-octadecene and dimethyl-9-octadecenoate, with a productive TON of 94900.

Boron-substituted 1,3-dienes and heterodienes as key elements in multicomponent processes.

In the last few years, multicomponent reactions involving boron substituted 1,3-dienes have emerged as important tools in synthetic organic chemistry. The most significant recent results and developments obtained in this area are reported in this review.

A novel, efficient synthesis of N-aryl pyrroles via reaction of 1-boronodienes with arylnitroso compounds.

A one-pot hetero-Diels-Alder/ring contraction cascade is presented from the reaction of 1-boronodienes and arylnitroso derivatives to derive N-arylpyrroles in moderate to good yields (up to 82%).

Tandem reactions involving 1-silyl-3-boryl-2-alkenes. New access to (Z)-1-fluoro-1-alkenes, allyl fluorides, and diversely α-substituted allylboronates.

The reactions of 1-silyl-3-boryl-2-alkenes with various electrophilic reagents (Selectfluor, N-halosuccinimides, benzhydryl, and propargylic alcohols in the presence of a Lewis acid, N-alkoxycarbonyliminium ion) have been investigated as new routes to α-substituted allylboronates. Further functional transformations, including allylboration, Suzuki coupling, protodeboronation, and cycloisomerization, have been carried out to illustrate the synthetic potential of these γ-borylallylsilanes.