A general and versatile approach to thermally generated N-heterocyclic carbenes

被引:160
作者
Nyce, GW
Csihony, S
Waymouth, RM
Hedrick, JL
机构
[1] Stanford Univ, Stanford, CA 94305 USA
[2] IBM Corp, Almaden Res Ctr, Ctr Polymer Interfaces & Macromol Assemblies, San Jose, CA 95120 USA
关键词
carbenes; nitrogen heterocycles; organic catalysis; organometallic complexes;
D O I
10.1002/chem.200400196
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The synthesis of N-heterocyclic carbene (NHC) adducts by condensation of diamines with appropriately substituted benzaldehydes is described. This simplified approach provides the NHC adduct without first having to generate the carbene followed by its protection. These adducts undergo thermal deprotection to generate N-heterocyclic carbene in situ. Adduct decomposition temperatures were investigated as a function of catalyst structure by using thermal analysis and spectroscopic techniques. Importantly, unlike adducts derived from chloroform, the new pentafluorobenzene-based adducts are more readily prepared and are stable at room temperature. The utility of these adducts as organic catalyst precursors for living ring-opening polymerization (ROP) of lactide, transesterification reactions, and the synthesis of N-heterocyclic carbene ligated organometallic complexes is also described.
引用
收藏
页码:4073 / 4079
页数:7
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