[show abstract][hide abstract] ABSTRACT: Borane (BH3) is a highly versatile reagent with widespread applications in organic synthesis. The commonly used borane reagents (BH3.THF and BH3:SMe2) have various disadvantages, including low borane concentration and low stability (BH3:THF) or a malodorous by-product (Me2S). A new, stable, easily handled and solid adduct of borane with a polymeric material containing sulfur was synthesised. The new material overcomes the disadvantages commonly associated with BH3:THF and BH3:SMe2 reagents. The stability and use of the adduct as a hydroborating and reducing agent was explored. Wider applications of the new borane adduct were tested by attempting various reactions. The results showed that the new polymeric borane adduct behaves similarly to BH3:THF and BH3:SMe2.
[show abstract][hide abstract] ABSTRACT: A new stable, easily handled and solid borane adduct from a polymeric material was synthesised. The new material overcomes the disadvantage commonly associated with BH3.THF and BH3.SMe2 reagents.1-3 The stability and use of the adduct as a hydroborating and reducing agent was explored.
1. Mark Potyen, Kanth V. B. Josyula, Mike Schuck, Sean Lu, Peng Gao and Chris Hewitt, Organic Process Research & Development, 2007, 11, 210-214
2. J.M. Clay and E. Vedejs, J. Am. Chem. Soc., 2005, 127, 5766.
3. H.C. Brown, US Patent, 1996, 5567849.
Poster (Ic.003) of EuCheMS Chemistry Congress; 08/2010
[show abstract][hide abstract] ABSTRACT: New polymeric borane adducts have been synthesized from polymeric sulfides, which are solids with a mild odour. The adducts have significant stability and reasonable solubility in THF. They act as hydroborating and reducing reagents with behaviour similar to that of borane-methyl sulfide, which makes them attractive borane sources.
Poster (H26_P07) of Macro 2010: 43rd IUPAC World Polymer Congress; 07/2010
[show abstract][hide abstract] ABSTRACT: Regioselective bromination of naphthalene with bromine in DCM over solid catalysts has been investigated. The process can be used for the production of 1-bromonaphthalene, 1,4-dibromonaphthalene, 1,5-dibromonaphthalene, 1,4,6 tribromonaphthalene, 1,2,4,6-tetrabromonaphthalene, and 1,2,4,6,7-pentabromonaphthalene. The structures of products have been confirmed by NMR and x-ray crystal structures. We are working to optimise the conditions for the production of specific dibromonaphthalenes by varying the types of solids.
Poster (IVc.057) of EuCheMS Chemistry Congress; 01/2010
[show abstract][hide abstract] ABSTRACT: Many commercial chemical processes are based on early chemical reactions for which selectivity is low. Examples include electrophilic substitution reactions of simple aromatic substrates like toluene, which typically give mixtures of mainly ortho- and para-substituted isomers. Such processes suffer from many disadvantages that are no longer acceptable, because processes are expected to be sustainable and to have minimal environmental impact.
There are three fundamentally different approaches to improving selectivity in such processes, involving modification of the substrate (e.g. activation so that it becomes more reactive at the position where substitution is required), the reagent or catalyst (designed so that it favours attack at the desired position), or the medium in which the reaction takes place (so that the desirable reaction becomes more favourable than the less desirable ones).
Abstracts (poster L-PO-44) of the 1st European Chemistry Congress; 08/2006
[show abstract][hide abstract] ABSTRACT: Organoborohydride reducing reagents are well known and extremely useful, but are often completely destroyed during the work-up of reactions in which they are employed. This is wasteful of material and can also create a problem of sepn. of the desired reaction product from those products derived by decompn. of the organoboron reagent. In turn, this results in further wastage of materials and in loss of time. On a com. scale this can mean the difference between viability or non-viability of a process.One way to circumvent these dificulties is to attach the reagent to a solid support so that it can be recovered easily by filtration. However, for this to be effective the reagent must be air-stable and robust and it must be easily reconverted back to its active form. In this paper we report the prepn. of some air-stable and regenerable polymer-supported organoborohydride reagents and describe some of their reactions.
Abstracts of Papers of the American Chemical Society, 1999, 218, 66; 08/1999