The metal‐catalysed hydrofunctionalisation of alkenes and alkynes provides a convenient and atom‐economic route to diversely functionalised products with control of regio‐, chemo‐ and stereoselectivity. As one of the most abundant elements on earth, iron offers a level of sustainable and long‐term availability that is uncommon for most transition metals. Although iron is commonly found in the oxidation states of +2 and +3, the use of redox‐active ligands has allowed the synthesis and application of low oxidation state iron complexes in catalysis. A broad range of hydrofunctionalisation reactions have been developed by using iron catalysts in a wide variety of oxidation states. Intense development over the past decade has resulted in the development of iron‐catalysed hydroamination, hydroalkoxylation, hydrocarboxylation, hydrothiolation, hydrovinylation, hydrosilylation, hydroboration, hydrophosphination, hydromagnesiation and carbonylation reactions, amongst others. With the field still in its infancy, there is great potential for further developments in the mechanistic understanding and synthetic and industrial applicability of these processes.

In tissue culture of hepatocytes, insulin (0.1-1 munits/ml for 4 h) reversed completely the effects of starvation of rats to decrease the activity of pyruvate dehydrogenase (PDH) complex and to increase the activities of PDH kinase and PDH kinase activator protein. It had no effect in hepatocytes from fed rats. Significant effects of insulin were detected with 0.01 munit/ml after 4 h, and in 1-2 h with 1 munit/ml.

The activities of pyruvate dehydrogenase (PDH) kinase and of PDH kinase activator protein (KAP) were increased 2-2.4-fold during 25 h of culture of hepatocytes from fed rats with glucagon plus n-octanoate. PDH kinase activity in hepatocytes from starved rats (initially 2.2 x fed control) fell during 25 h of culture in medium 199 (to 1.5 x fed control), but was maintained by glucagon plus octanoate. Dibutyryl or 8-bromo cyclic AMP increased PDH kinase activity 2-2.2-fold in hepatocytes from fed rats, but phenylephrine and isoproterenol (isoprenaline) were without effect. Insulin blocked the action of glucagon to increase PDH kinase activity and decreased the effect of octanoate and octanoate plus glucagon. It is suggested that the effects of starvation to increase activities of PDH kinase and of KAP in liver are mediated by alterations in circulating concentrations of glucagon, fatty acids and insulin and in hepatic cyclic AMP.