Compounds Containing Intramolecularly Coordinating Substituents

Diorganozinc Compounds Containing Intramolecularly Coordinating Substituents 

All compounds have comparable structural features, the hydrocarbon chains being coiled back to allow the donor atom to coordinate to zinc. The Zn—C bond distances 

Johann T. B. H. Jastrzebski, Jaap Boersma and Gerard van Koten 

FIGURE 35. Molecular geometry of the (i ,i )-diastereoisomer of 68 in the soUd state 

---

C. Diorganozinc Compounds Containing Intramolecularly Coordinating Substituents... 

It is rather surprising that only a few diorganomagnesium compounds have been reported in which intramolecular coordination of a heteroatom-containing substituent is present. The synthesis of (2-Me2NCH2C6H4)2Mg (67) was reported. It has been used in a study on the infiuence of the presence of potentially intramolecular coordinating substituents on Schlenk equilibria However, it has never been structurally characterized. 

Corriu and coworkers found that the reaction of the pentacoordinated functionalized silane 6 (see also Sections II.B.l and II.C.l) with elemental selenium leads to a stable silaneselone 140, which is stabilized by intramolecular coordination of the nitrogen-containing substituent to the doubly-bonded silicon (Scheme 42) . Although the structure of 140 was supported by Si and NMR and MS spectra, including a downfield Si chemical shift (S = -1-29.4) and a high coupling constant with Se (JseSi = 257 Hz), neither the crystallographical structure analysis nor the reactivity of this isolable Si=Se compound has been reported. 

---