Metathesis reactions with a low-cost spinning disk system

Abstract

Experimental procedures have been developed to provide at the laboratory scale an efficient and relatively inexpensive continuous flow processing system to undertake metathesis chemistry. Glass discs, coated with porous silica particles impregnated with Grubbs (I) generation or Hoveyda-Grubbs (II) generation catalysts through non-covalent interactions, have been successfully used as annular zones for in situ metathesis reactions. The supported catalysts were active for ring closing metathesis and self-metathesis reactions with a variety of substrates with nearly quantitative conversion depending on the substrate structure. Advantages of these procedures include the ability to conduct reactions efficiently at small (low mmole) scale under ambient laboratory conditions, thereby avoiding the need for high energy/thermal procedures. Multiple experiments can be undertaken during the same day if catalyst screening is required. Moreover, separation of starting materials from products can be achieved using the same unit operations, avoiding the need for additional purification steps, thereby reducing the total solvent consumption.

Experimental and computational studies of an antiplasmodial derivative of allantoin; antimycobacterial essential oil from Cordia batesii WERNHAM (Boraginaceae)

“…1 ). Their assignments were consistent with structures of: allantoin ( 1 ) [ 32 ], pyrimidine 2,4-(1 H ,3 H )-dione ( 3 ) [ 33 ], cordialin A ( 4 ) and cordialin B ( 5 ) [ 34 ], quercetin ( 6 ) [ 35 ], myricetin ( 7 ) [ 36 ], genistein 4′- O -glucuronide ( 8 ) [ 37 ], methyl palmitate ( 9 ) [ 38 ], palmitic acid ( 10 ) [ 39 ], methyl (9 E ,12 E )-octadeca-9,12-dienoate ( 11 ) [ 40 ], methyl oleate ( 12 ) [ 41 ], methyl tridecanoate ( 13 ) [ 42 ] and ( Z )-octadec-11-enoic acid ( 14 ) [ 43 ].

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Challenges Arising from Continuous‐Flow Olefin Metathesis

“…[23] Looking to harness these attributes for a continuous metathesis process, Hearn and co-workers developed an SDR which uses a glass disk loaded with porous silica which was impregnated with G-I catalyst to perform ring-closing metathesis when the reactants flow across the surface (Scheme 12). [24] In addition, the reaction products could be easily and concomitantly separated by simple in situ solvent elution methods. Good to excellent yields were observed for all examples with mixtures of both single-and doublemetathesis products shown for examples with two bis-allyl groups.…”

Density Functional Theory of a New Derivative of Allantoin with Antiplasmodial Properties, Antimycobacterial Activities of Essential Oil from Cordia Batesii WERNHAM (Boraginaceae)

“…1). Their assignments were consistent with structures of: allantoin (1) [15,27], pyrimidine 2,4-(1H,3H)-dione (3) [28], cordialin A (4) and cordialin B (5) [29], quercetin (6) [30], myricetin (7) [31], genistein 4'-O-glucuronide (8) [32], methyl palmitate (9) [33], palmitic acid (10) [34], methyl (9E,12E)-octadeca-9,12-dienoate (11) [35], methyl oleate (12) [36], methyl tridecanoate (13) [37] and (Z)-octadec-11-enoic acid ( 14) [38]. 6)] ppm (Table 1).…”