Introduction and Historical

In the late 1970 s, Kirchhoff at The Dow Chemical Company initiated a research program on the use of benzocyclobutenes in polymer synthesis and modification. These efforts culminated in 1985 with the issuance of the first patent on the use of benzocyclobutenes in the synthesis of high molecular weight polymers [3]. Similar work was reported separately and independently by Tan and Arnold working at the Air Force Wright Laboratories [11-14], Since these initial discoveries, the field of benzocyclobutene polymers has rapidly expanded to include currently 75 issued patents and numerous publications by a variety of researchers. These numbers are expected to increase considerably since benzocyclobutenes constitute the basis of a new and versatile approach to the synthesis of high performance polymers for applications in the electronics and aerospace industries. 

Bisbenzocyclobutenes readily react with molecules which contain sites of reactive unsaturation such as bismaleimides [10,13, 31, 32]. This is in essence, a novel type of Diels-Alder polymerization in which the bis-diene is latently embodied within two benzocyclobutene moieties. The properties of these polymers depends strongly on the mole ratio of the monomers and when it is equimolar, can result in some exceptionally tough high Tg resins [33, 34]. 

---

Enantioselective Alkene Hydrogenation Introduction and Historic Overview... 

---