Search results
Results from the WOW.Com Content Network
Hydroboration–oxidation is an anti-Markovnikov reaction, with the hydroxyl group attaching to the less-substituted carbon. The reaction thus provides a more stereospecific and complementary regiochemical alternative to other hydration reactions such as acid-catalyzed addition and the oxymercuration–reduction process.
Oxymercuration is very regioselective and is a textbook Markovnikov reaction; ruling out extreme cases, the water nucleophile will always preferentially attack the more substituted carbon, depositing the resultant hydroxy group there.
Many alternative routes are available for producing alcohols, including the hydroboration–oxidation reaction, the oxymercuration–reduction reaction, the Mukaiyama hydration, the reduction of ketones and aldehydes and as a biological method fermentation.
Hydroboration of trisubstituted alkenes places boron on the less substituted carbon. [7] Hydroboration of 1,2-disubstituted alkenes, such as a cis or trans olefin, produces generally a mixture of the two organoboranes of comparable amounts, even if the steric properties of the substituents are very different. For such 1,2-disubstituted olefins ...
Methylcyclopentane is an organic compound with the chemical formula CH 3 C 5 H 9.It is a colourless, flammable liquid with a faint odor. It is a component of the naphthene fraction of petroleum usually obtained as a mixture with cyclohexane.
Catalyzed hydroboration-oxidation of substituted alkenes can be rendered enantioselective. In 1990, Brown and co-workers achieved asymmetric hydroboration using an achiral catalyst and chiral borane sources derived from ephedrine and pseudoephedrine. In most cases, the regioselectivity was poor although the ee values can be close to 90%. [16]
AA’s meetings, with their folding chairs and donated coffee, were intended as a judgment-free space for addicts to talk about their problems. Treatment facilities were designed for discipline. Something else has been lost with the institutionalization of the 12 steps over the years: Bill Wilson’s openness to medical intervention.
Wilkinson's catalyst also catalyzes many other hydrofunctionalization reactions including hydroacylation, hydroboration, and hydrosilylation of alkenes. [14] Hydroborations have been studied with catecholborane and pinacolborane. [15] It is also active for the hydrosilylation of alkenes. [16]