被 sp(3) 碳双螺旋包围的 sp 碳链：通过烯烃复分解反应定向合成由两个 P(CH₂)ₘP 键连接的线状 Pt(CC)ₙPt 部分。
sp carbon chains surrounded by sp(3) carbon double helices: directed syntheses of wirelike Pt(CC)(n)Pt moieties that are spanned by two P(CH(2))(m)P linkages via alkene metathesis.
作者信息
de Quadras Laura, Bauer Eike B, Mohr Wolfgang, Bohling James C, Peters Thomas B, Martín-Alvarez José Miguel, Hampel Frank, Gladysz John A
机构信息
Institut für Organische Chemie and Interdisciplinary Center for Molecular Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
出版信息
J Am Chem Soc. 2007 Jul 4;129(26):8296-309. doi: 10.1021/ja071612n. Epub 2007 Jun 13.
Reactions of trans-(C6F5)(Ph2P(CH2)m'CH=CH2)2PtCl (1; m' = a, 6; b, 7; c, 8; d, 9; e, 10) and H(CC)2H (HNEt2, cat. CuI) give trans-(C6F5)(Ph2P(CH2)m'CH=CH2)2Pt(CC)2H (3a-e, 80-95%). Oxidative homocouplings of 3a-d under Hay conditions (O2, cat. CuCl/TMEDA, acetone) yield trans,trans-(C6F5)(Ph2P(CH2)m'CH=CH2)2Pt(CC)4Pt(Ph2P(CH2)m'CH=CH2)2(C6F5) (4a-d, 64-84%). Treatment of 3c-e with excess HCCSiEt3 under Hay conditions gives trans-(C6F5)(Ph2P(CH2)m'CH=CH2)2Pt(CC)3SiEt3 (56-73%). Homocouplings (n-Bu4N+ F-, Me3SiCl, Hay conditions) afford trans,trans-(C6F5)(Ph2P(CH2)m'CH=CH2)2Pt(CC)6Pt(Ph2P(CH2)m'CH=CH2)2(C6F5) (13c-e, 59-64%). Reactions of 4a-d and 13c-e with Grubbs' catalyst, followed by hydrogenation, give mixtures of trans,trans-(C6F5)(Ph2P(CH2)mPPh2)Pt(CC)nPt(Ph2P(CH2)mPPh2)(C6F5) with termini-spanning diphosphines and trans,trans-(C6F5)(Ph2P(CH2)mPPh2)Pt(CC)nPt(Ph2P(CH2)mPPh2)(C6F5) with trans-spanning diphosphines (m = 2m' + 2; n = 4, 6). The latter (n = 4) are independently synthesized by similar metatheses/hydrogenations of 1a-d to give trans-(C6F5)(Ph2P(CH2)mPPh2)PtCl (49-59%), followed by analogous introductions of (CC)4 chains (66-77%). Crystal structures of complexes with termini-spanning diphosphines show sp3 chains with both double-helical (m/n = 20/4) and nonhelical (m/n = 20/6) conformations, and highly shielded sp chains. The sp3 chains of complexes with trans-spanning diphosphines exhibit double half-clamshell conformations. The dynamic properties of both classes of molecules are analyzed in detail.
反式-(C6F5)(Ph2P(CH2)m'CH=CH2)2PtCl（1；m' = a，6；b，7；c，8；d，9；e，10）与H(CC)2H（HNEt2，催化量的CuI）反应生成反式-(C6F5)(Ph2P(CH2)m'CH=CH2)2Pt(CC)2H（3a - e，产率80 - 95%）。3a - d在Hay条件下（O2，催化量的CuCl/TMEDA，丙酮）进行氧化均偶联反应，生成反式，反式-(C6F5)(Ph2P(CH2)m'CH=CH2)2Pt(CC)4Pt(Ph2P(CH2)m'CH=CH2)2(C6F5)（4a - d，产率64 - 84%）。在Hay条件下，用过量的HCCSiEt3处理3c - e，得到反式-(C6F5)(Ph2P(CH2)m'CH=CH2)2Pt(CC)3SiEt3（产率56 - 73%）。均偶联反应（n - Bu4N+F-，Me3SiCl，Hay条件）得到反式，反式-(C6F5)(Ph2P(CH2)m'CH=CH2)2Pt(CC)6Pt(Ph2P(CH2)m'CH=CH2)2(C6F5)（13c - e，产率59 - 64%）。4a - d和13c - e与Grubbs催化剂反应，随后氢化，得到具有端基跨连二膦配体的反式，反式-(C6F5)(Ph2P(CH2)mPPh2)Pt(CC)nPt(Ph2P(CH2)mPPh2)(C6F5)和具有反式跨连二膦配体的反式，反式-(C6F5)(Ph2P(CH2)mPPh2)Pt(CC)nPt(Ph2P(CH2)mPPh2)(C6F5)的混合物（m = 2m' + 2；n = 4，6）。后者（n = 4）通过1a - d进行类似的复分解/氢化反应独立合成，得到反式-(C6F5)(Ph2P(CH2)mPPh2)PtCl（产率49 - 59%），随后进行类似的引入(CC)4链的反应（产率66 - 77%）。具有端基跨连二膦配体的配合物的晶体结构显示出具有双螺旋（m/n = 20/4）和非螺旋（m/n = 20/6）构象的sp3链，以及高度屏蔽的sp链。具有反式跨连二膦配体的配合物的sp3链呈现双半蛤壳构象。对这两类分子的动力学性质进行了详细分析。
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