UMR CNRS 5250, Département de Chimie Moléculaire, Université Grenoble-Alpes, B. P. 53, 38041, Grenoble, France.
UCSD Crystallography Facility, La Jolla, CA, 92093-0343, USA.
Angew Chem Int Ed Engl. 2017 Jan 19;56(4):1031-1035. doi: 10.1002/anie.201610798. Epub 2016 Dec 20.
Complexes of the ubiquitous β-diketiminates (NacNac) ligands have been reported with most elements of the periodic table, including Group 14 Si, Ge, Sn, and Pb. The striking absence of carbon representatives has been attributed to the extreme electrophilicity of the putative C-NacNac adducts. An electron enriched 2,4-(dimethylamino)diketiminato backbone is described, which allowed for the synthesis and isolation of such stable pyrimidin-1,3-diium and pyrimidinium-2-ylidene salts. Structural and preliminary reactivity studies are reported, including an air-stable gold complex. An unforeseen original class of stable N-heterocyclic carbenes and, more generally, the potential of electron-rich NacNac patterns for taming highly electrophilic centers are showcased.
已报道了普遍存在的β-二酮亚胺配体（NacNac）与周期表中的大多数元素形成的配合物，包括第 14 族的 Si、Ge、Sn 和 Pb。令人惊讶的是，没有碳代表物，这归因于假定的 C-NacNac 加合物的极端亲电性。本文描述了一种富电子的 2,4-（二甲基氨基）二酮亚胺骨架，允许合成和分离这种稳定的嘧啶-1,3-二𬭩和嘧啶-2-亚基盐。报道了结构和初步反应性研究，包括一种空气稳定的金配合物。展示了一类意想不到的稳定的 N-杂环卡宾，更普遍地说，富电子 NacNac 模式用于驯服高亲电性中心的潜力。
