One-Pot Dehydrogenative Addition of Isopropyl to Alkynes Promoted by Osmium: Formation of -(mg src="http://pubs.acs.org/images/gif

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• 作者：Miguel A. Esteruelas ; Yohar A. Hern&aacute ; ndez ; Ana M. L&oacute ; pez ; Montserrat Oliv&aacute ; n ; Enrique Oñ ; ate
• 刊名：Organometallics
• 出版年：2007
• 出版时间：April 23, 2007
• 年：2007
• 卷：26
• 期：9
• 页码：2193 - 2202
• 全文大小：209K
• 年卷期：v.26,no.9(April 23, 2007)
• ISSN：1520-6041

文摘

The dihydride-dihydrogen complex [OsH₂(mages/gifchars/eta.gif" BORDER=0 >⁵-C₅H₅)(mages/gifchars/eta.gif" BORDER=0 >²-H₂)(PⁱPr₃)]BF₄ (1) reacts in acetone with1-phenyl-1-propyne and 2-butyne to give the mages/gifchars/gamma.gif" BORDER=0 >-(mages/gifchars/eta.gif" BORDER=0 >³-allyl)-mages/gifchars/alpha.gif" BORDER=0>-alkenylphosphine derivatives [OsH(mages/gifchars/eta.gif" BORDER=0 >⁵-C₅H₅){mages/gifchars/kappa.gif" BORDER=0 >⁴-(P,C,C,C)-CH₂C[CH₂C(=CH₂)PⁱPr₂]CHR}]BF₄ (R = Ph (2), CH₃ (3)), by means of one-pot tandemprocesses of four reactions. The stable intermediates have been isolated and characterized. In acetone,complex 1 dissociates H₂ and coordinates the solvent to afford [OsH₂(mages/gifchars/eta.gif" BORDER=0 >⁵-C₅H₅)(mages/gifchars/kappa.gif" BORDER=0 >¹-OCMe₂)(PⁱPr₃)]BF₄(4), which reacts with a molecule of 1-phenyl-1-propyne or 2-butyne to form [OsH(mages/gifchars/eta.gif" BORDER=0 >⁵-C₅H₅)(mages/gifchars/eta.gif" BORDER=0 >³-CH₂CHCHR)(PⁱPr₃)]BF₄ (R = Ph (5), CH₃ (6)), containing the CHR group cisoid disposed to the phosphineand the R substituent anti to C_meso. In dichloromethane, complexes 5 and 6 evolve to the thermodynamicisomers 7 and 8, containing the CHR group cisoid disposed to the hydride and the R substituent syn toC_meso. The reactions of 5 and 6 with a second molecule of the respective alkyne lead to the correspondingZ-olefin and [Os(mages/gifchars/eta.gif" BORDER=0 >⁵-C₅H₅){mages/gifchars/eta.gif" BORDER=0 >²-(Z)-CH(CH₃)=CHR}{mages/gifchars/kappa.gif" BORDER=0 >³-(P,C,C)-[CH₂=C(CH₃)]PⁱPr₂}]BF₄ (R = Ph (9),CH₃ (10)). The isopropenyl group of the phosphine of 9 and 10 undergoes coupling with a third alkynemolecule to give 2 and 3.