Cage Phosphinites: Ligands for Efficient Nickel-Catalyzed Hydrocyanation of 3-Pentenenitrile

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• 作者：Igor S. Mikhel ; Michael Garland ; Jonathan Hopewell ; Sergio Mastroianni ; Claire L. McMullin ; A. Guy Orpen ; Paul G. Pringle
• 刊名：Organometallics
• 出版年：2011
• 出版时间：March 14, 2011
• 年：2011
• 卷：30
• 期：5
• 页码：974-985
• 全文大小：1055K
• 年卷期：v.30,no.5(March 14, 2011)
• ISSN：1520-6041

文摘

The cage monophosphinites CgPOR {where CgP = 6-phospha-2,4,8-trioxa-adamantane and R = C<sub>6sub>H<sub>5sub> (L<sub>asub>); 2-C<sub>6sub>H<sub>4sub>CH<sub>3sub> (L<sub>bsub>); 2,4,6-C<sub>6sub>H<sub>2sub>(CH<sub>3sub>)<sub>3sub> (L<sub>csub>); 2,4-C<sub>6sub>H<sub>3sub><sup>tsup>Bu<sub>2sub> (L<sub>dsub>); CH<sub>3sub> (L<sub>esub>); CH<sub>2sub>CF<sub>3sub> (L<sub>fsub>)} and diphosphinites CgPZPCg {where ZH<sub>2sub> = 2,2鈥?biphenol (L<sub>gsub>) or 1,2-benzenedimethanol (L<sub>hsub>)} have been made from CgPBr and the corresponding alcohol or phenol. The cage phosphinites are remarkably stable to water. All the ligands L<sub>a鈭抙sub> have been tested for nickel(0)-catalyzed hydrocyanation of 3-pentenenitrile in the presence of Lewis acids (ZnCl<sub>2sub>, Ph<sub>2sub>BOBPh<sub>2sub>, or <sup>isup>Bu<sub>2sub>AlOAl<sup>isup>Bu<sub>2sub>), and tentative structure鈭抋ctivity relationships are suggested. The hydrocyanation activities obtained with catalysts derived from monophosphinite L<sub>fsub> (with <sup>isup>Bu<sub>2sub>AlOAl<sup>isup>Bu<sub>2sub>) and diphosphinite L<sub>hsub> (with ZnCl<sub>2sub>) are comparable with the commercial catalyst based on P(OTol)<sub>3sub>. The complexes trans-[PtCl<sub>2sub>(L)<sub>2sub>] where L = L<sub>asub> (1a), L<sub>esub> (1e), and L<sub>fsub> (1f) and the chelate cis-[PtCl<sub>2sub>(L<sub>hsub>)] (1h) are reported. From the 谓<sub>COsub> values for the complexes trans-[RhCl(CO)(L<sub>a鈭抐sub>)<sub>2sub>] (2a鈭?b>f), it is concluded that ligand L<sub>fsub> is the most phosphite-like of the monophosphinites. Treatment of [Ni(cod)<sub>2sub>] (cod = 1,5-cyclo-octadiene) with L<sub>hsub> leads to a mixture of products, one of which was characterized as the binuclear [Ni<sub>2sub>(L<sub>hsub>)<sub>2sub>(渭-cod)] (3h). The crystal structures of L<sub>hsub>, 1a, 1e, 1f, 1h路2CH<sub>2sub>Cl<sub>2sub>, and 3h路3C<sub>6sub>H<sub>5sub>CH<sub>3sub> are reported.