uranocenes show ease of reduction of u(iv) compounds to u(iii) compounds; otherwise they are fairly unreactive. a close relative that does have sufficient reactivity, obtained by reaction of uranocene with uranium borohydride is the half-sandwich compound (cot)u(bh) discovered in 1983 by the group of m.j. ephritikhine. compounds of this type react in many different ways, for instance alkylation at uranium with organolithium reagents or conversion to hybrid sandwich compounds.