The mechanism study on Pd(0)-catalyzed cyclization of non-terminal alkynols under molecular level shows that the alkynols prefer to form endocyclic ethers in the present of Pd₂(dba)₃ and Xantphos rather than exocyclic ethers , which is attributed to the steric hindrance of Xantphos. With the help of the large bulk of metal complexe, reaction point can be regiocontrolled so as to synthesize compounds selectively. The vacant d orbital of Pd atom can accommodate electrons, which is the key point for the binding of C-O bond. This step has to overcome a free energy barrier of 17.1kcal/mol to form exocyclic ethers while it only needs 15.0kcal/mol free energy barrier to to form endocyclic ethers. The analysis of NBO charges and molecular orbital also demonstrate that it is more favorable to form endocyclic ethers with Pd₂(dba)₃ and Xantphos.

在分子水平下Pd（0）催化非末端炔醇环化的机理研究表明，炔醇更倾向于在Pd ₂（dba）₃和Xantphos的存在下形成环内醚，而不是环外醚，这归因于Xantphos的空间位阻。借助于大量的金属配合物，可以控制反应点，从而选择性地合成化合物。空缺dPd原子的轨道可以容纳电子，这是结合CO键的关键。该步骤必须克服17.1kcal / mol的自由能垒以形成环外醚，而仅需要15.0kcal / mol的自由能垒以形成内环醚。对NBO电荷和分子轨道的分析还表明，与Pd ₂（dba）₃和Xantphos形成内环醚更为有利。