已经通过吡啶-2-硫代氧羰基(PTOC)竞争动力学方法在单个浓度点上确定了壬基从20种N-杂环卡宾和硼烷(NHC-硼烷)的络合物中提取氢的速率常数。速率常数的范围是从<1×10 4到8×10 4 M -1 s -1。它们几乎不依赖于卡宾核的电子性质,但是存在随着卡宾N取代基尺寸的减小而增加速率常数的趋势。已经鉴定出两种有希望的具有小的N取代基的新试剂(R = Me)。
The investigation of the electronic and steric properties of 4,5-disubstituted imidazolylidenes is reported, as well as their successful application as organocatalysts in the formation of gamma-butyrolactones by conjugate Umpolung.