Aldehyde From alkene

The synthesis of aldehydes from alkenes known as hydroformylation using CO and hydrogen and a homogeneous catalyst is a very important industrial process [204]. Today, over seven million tons of oxoproducts are formed each year using this procedure, with the majority of butanal and butanol from propene. To further increase the efficiency of this process it can be combined with other transformations in a domino fashion. Eilbracht and coworkers [205] used a Mukaiyama aldol reaction as a second step, as shown for the substrate 6/2-63 which, after 3 days led to 6/2-65 in 91% yield via the primarily formed adduct 6/2-64 (Scheme 6/2.13). However, employing a reaction time of 20 h gave 6/2-64 as the main product. 

As mentioned in the introduction, hydroformylation is an important industrial process used for the formation of aldehydes from alkenes. Some six million... 

This reaction is important for a number of reasons. It is an industrial synthesis of aldehydes from alkenes by the addition of carbon monoxide and hydrogen in the presence of a cobalt catalyst. A prime example is the synthesis... 

These protocols can be regarded as promising because of their simplicity and broad scope. The conventional method for the production of aldehydes from alkenes consists of ozonolysis followed by workup under reducing conditions [72]. The ruthenium-based method, using either oxone or NaI04 as the oxidant, is an interesting alternative. The high selectivity to aldehyde versus carboxylic acid was reached by manipulation of the amount of terminal oxidant (2 Eq.) and the reaction time. 

Hydroformylation is a useful catalytic method for the synthesis of aldehydes from alkenes and alkynes. There are no other methods that compete directly with hydroformylation for the synthesis of alkyl aldehydes. However, when the desired compounds are carboxylic acids or esters, and aldehydes are used as their... 

The last catalytic reaction we examine in this overview is the Wacker oxidation of ethylene to acetaldehyde with O2, now used to make about 4 million tons a year of aldehydes from alkenes. This reaction shows several new features of great interest. Although the work started with a commonplace observation— the stoichiometric oxidation of alkenes by Pd(II) salts with formation of Pd(0)— the authors were able to make the system catalytic by finding a clean way to reoxidize the Pd(0) to Pd(II) with air. The mechanism was obscure for years because the kinetics gave an incomplete picture and it was only with sophisticated labeling studies that the currently accepted mechanism was discovered. 

What roles do inorganic catalysts play in the following manufacturing processes (a) production of aldehydes from alkenes, (b) polymerization of propene, (c) production of acetic anhydride,... 

---