Fine-Tunable 3,4-Dihydroquinazol-2-ylidene Carbenes: Synthesis, Rhodium(I) Complexes, and Reactivity
作者:Jun Zhang、Xinke Qin、Jun Fu、Xiao Wang、Xiaolong Su、Fangle Hu、Jiajun Jiao、Min Shi
DOI:10.1021/om300887y
日期:2012.12.10
The design and synthesis of various new six-membered cyclic formamidinium salts with a 3,4-dihydroquinazoline core have been reported in this paper. Our synthetic strategy allows access to a kind of tailor-made 3,4-dihydroquinazolinium salts bearing different substituent combinations. A series of novel 3,4-dihydroquinazolin-2-ylidene-based rhodium(I) complexes were prepared by the reaction of [Rh(cod)Cl]2
本文报道了具有3,4-二氢喹唑啉核心的各种新型六元环甲form盐的设计与合成。我们的合成策略允许获得一种带有不同取代基组合的量身定制的3,4-二氢喹唑啉盐。通过[Rh(cod)Cl] 2与相应的3,4脱质子化获得的游离卡宾的反应,制备了一系列新型的3,4-二氢喹唑啉-2-亚烷基铑(I)配合物-二氢喹唑啉盐与KN(SiMe 3)2。原位制备的NHC也可以与S 8或CS 2反应,得到相应的硫酮或NHC–CS 2加合物。铑(I)配合物被转化为相应的二羰基配合物,相应的二羰基Rh配合物的ν(CO)值表明3,4-二氢喹唑-2-亚基比普通的五元NHC更强的电子供体。Rh络合物在羰基化合物的芳基化反应中具有很高的活性,去质子化后原位制备的3,4-二氢喹唑啉-2-亚烷基在钯催化的Suzuki交叉偶联反应中,在室温下具有ppm级的催化剂负载能力非常强。吨高达425 000。