Lead reagents are often used in organic synthesis, as they have the ability to drive reactions such as carbon-carbon bond cleavage, ring-formation, oxidation of alcohols, and especially oxidative arylation. A type of lead reagent frequently used is organolead triacetate. Organolead triacetates have a tendency to react regioselectively, favoring quaternary carbon centers. This is illustrated especially in their reaction with phenols and dicarbonyls. This unique characteristic of organolead triacetates allows them to form highly hindered products. As shown in the figure above of a characteristic reaction involving an organolead triacetate, the lead reagent allows for the formation of a quaternary center instead of a tertiary one.
Another typical lead reagent is Pb(0), which acts as a reducing agent in many reactions by giving up its electrons to the molecule it is reacting with. Once lead is oxidized to Pb(II), it can then be used as a catalytic Lewis Acid since it has a 2+ charge and is very willing to accept electrons, as shown in the figure below.
Finally, lead tetraacetate is also used frequently in organic synthesis due to its electrophillic nature.It is very often used in the oxidation of tertiary alcohols to ketones. A reaction involving lead tetraacetate is depicted below, where the lead compound attaches itself to the nucleophilic oxygen atom, and then functions as an electron accepting Lewis acid to aid in the formation of a ketone from an alcohol. In this case, lead tetraacetate is reduced to Lead (II) Acetate, a very common lewis acid.
References:
Alvarez-Manzaneda, E. J.; Chahboun, R.; Cano, M. J.; Torres, E. C.; Alvarez, E.; Alvarez-Manzaneda, R.; Haidour, A.; López, J. M. R. Tetrahedron Lett. 2006, 47, 6619-6622.
Kano, T.; Saito, S. Main Group Metals in Organic Synthesis; Wiley-VCH Verlag GmbH & Co. KGaA: Weinham, 2004; pp 721-748.
Pinhey, J. T. Pure & Appl. Chem. 1996, 68(4), 819-824.
Sheldon, R. A.; Kochi, J. K. Organic Reactions; John Wiley & Sons: Chicester, U.K., 2011; pp 279-421.
