Regioselective CH Bond Activation on Stabilized Nitrogen Ylides Promoted by Pd(II) Complexes: Scope and Limitations
作者:Loreto Grande、Elena Serrano、Luciano Cuesta、Esteban P. Urriolabeitia
DOI:10.1021/om201001c
日期:2012.1.9
studied. The incorporation of the Pd atom to these substrates is regioselective, since the orthopalladation is produced, in most of the cases, only at the aryl ring of the benzoyl group with concomitant C-bonding of the N-ylide. The X-ray structure of one representative example is reported. Factors governing the observed orientation are discussed, because this regioselectivity is worthy of note, considering
已经研究了N-基化物[H x C y N–CHC(O)Ar]的原palpalladation (H x C y N =吡啶,苄胺,咪唑,苯胺和苯基吡啶; Ar =芳基)。Pd原子结合到这些底物上是区域选择性的,因为在大多数情况下,仅在苯甲酰基的芳环上产生原钯,并伴随着N-内酯的C键。报告了一个代表性实例的X射线结构。讨论了控制观察到的取向的因素,因为考虑到羰基的失活性质,这种区域选择性是值得注意的。已观察到总体趋势的两个例外。第一个是叶立德[PhMe 2NCHC(O)Ph],在每个Ph处都掺入一个Pd。第二个是在吡啶2-苯环上发生的苯基吡啶衍生物的palpalation,并生成六元的palladacycle。
Base catalysed rearrangements involving ylide intermediates. Part 15. The mechanism of the Stevens [1,2] rearrangement
作者:W. David Ollis、Max Rey、Ian O. Sutherland
DOI:10.1039/p19830001009
日期:——
The Stevens [1,2] rearrangement of acyl-stabilised ammoniumylides has been investigated with regard to stereoselectivity, intramolecularity and the formation of products in addition to the [1,2] rearrangementproduct. A detailed study of the effects of reaction conditions upon the rearrangement of the ylidederivedfrom the salt (13) has shown that the stereoselectivity (retention of the configuration