中文摘要：

过渡金属杂环化合物特别是过渡金属杂小环化合物(成环原子数小于6)在金属有机化学和配位化学领域中具有重要的地位,它们是许多过渡金属催化反应包括烯烃复分解反应、炔烃聚合反应的中间体.通常过渡金属杂小环化合物具有较大的环张力,因此极易与不饱和化合物反应生成环张力较小的扩环产物.针对过渡金属杂小环化学研究现状,综述了几类典型的过渡金属杂三、四、五元环的扩环反应.

英文摘要：

Metallacycles, especially those small rings, play an important role in the field of organometallic and coordination chemistry. They are considered as reactive intermediates in metal promoted or catalyzed reactions including olefin metathesis reactions and alkyne polymerization reactions. Due to the high ring strain, small metallacycles can easily react with unsatu-rated compounds to produce ring expansion products with lower ring strain. To further understand the importance of small metallacycle intermediates in the catalytic reactions and synthesis methodology, the ring expansion reactions of several typical three-, four-and five-membered metallacycles is summarize.