C-H ACTIVATION BY AQUEOUS PLATINUM COMPLEXES - A MECHANISTIC STUDY

被引：138

作者：

LUINSTRA, GA ^{[1
]}

WANG, L ^{[1
]}

STAHL, SS ^{[1
]}

LABINGER, JA ^{[1
]}

BERCAW, JE ^{[1
]}

机构：

[1] CALTECH,ARNOLD & MABEL BECKMAN LABS CHEM SYNTHESIS,PASADENA,CA 91125

来源：

JOURNAL OF ORGANOMETALLIC CHEMISTRY | 1995年 / 504卷 / 1-2期

关键词：

PLATINUM; C-H ACTIVATION;

D O I：

10.1016/0022-328X(95)05567-9

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Detailed mechanistic studies are reported on the oxidation of alkanes by aqueous [PtCl6](2-)/[PtCl4](2-) to alcohols plus alkyl chlorides, via proposed (alkyl)Pt-II and (alkyl)Pt-IV intermediates. Reactions of [PtCl4](2-) with RI (R=CH3, CH2CH2OH) in water yield [PtCl(5)R](2-), which were isolated as their NMe(4) salts. Kinetic rate laws of their decomposition in aqueous chloride solution to ROH and RCl support S(N)2 displacement by Cl- or H2O as the mechanism of the last step. erythro- and threo-[PtCl5(CHDCHDOH)](2-) are obtained by oxidation of [PtCl3(trans- and cis-CHD=CHD)](-) respectively, and react with Cl- with inversion of stereochemistry at carbon, consistent with the S(N)2 mechanism. [PtCl5(CH2CH2OH)](2-) is also obtained by oxidation of Zeise's salt with [PtCl6](2-). Kinetics indicate that attack of water on coordinated ethylene to give a beta-hydroxyethyl group precedes oxidation of Pt-II to Pt-IV, rather than the reverse order, and that this reaction is a model for the oxidation of(alkyl)Pt-II to (alkyl)Pt-IV during alkane functionalization. Pt-195 isotopic labeling demonstrates that the oxidation is not accompanied by transfer of the beta-hydroxyethyl group from one Pt center to another.

引用

页码：75 / 91

页数：17

共 31 条

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