Pivaloylmetals (
<i>t</i>
Bu‐COM: M=Li, MgX, K) as Equilibrium Components
作者:R. Knorr、G. Böhrer、B. Schubert、P. Böhrer
DOI:10.1002/chem.201102867
日期:2012.6.11
Short‐lived pivaloylmetals, (H3C)3C‐COM, were established as the reactive intermediates arising through thermal heterolytic expulsion of O=CtBu2 from the overcrowded metal alkoxides tBuC(=O)‐C(‐OM)tBu2 (M=MgX, Li, K). In all three cases, this fission step is counteracted by a faster return process, as shown through the trapping of tBu‐COM by O=C(tBu)‐C(CD3)3 with formation of the deuterated starting
短寿命的新戊酰金属(H 3 C)3 C-COM被确定为通过过度拥挤的金属醇盐t BuC(= O)-C(-OM)中O = C t Bu 2的热异质驱除而产生的反应性中间体t Bu 2(M = MgX,Li,K)。在所有这三种情况下,裂变步骤都可以通过更快的返回过程来抵消,如通过O = C(t Bu)-C(CD 3)3截留t Bu-COM并形成氘代起始醇盐所示。如果在不存在捕集剂的情况下产生,则所有三个t Bu-COM物种都会“二聚化”,从而得到烯醇化物MO-C(t Bu)= C(t Bu)-OM以及O = C t Bu 2(2当量)。通过剩余O = C t Bu 2进行的共模速率降低证明存在一些自由t Bu-COM(与O = C t Bu 2分开);但是必须假定具有未分离复合物特征的伴随中间体,例如t Bu-COM&O = C t Bu 2。在THF中生成t Bu-COMgX的慢裂变步骤使二