Roy Dipak Kumar, Mondal Bijan, Anju R S, Ghosh Sundargopal
Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 (India).
Chemistry. 2015 Feb 23;21(9):3640-8. doi: 10.1002/chem.201405218. Epub 2014 Dec 23.
Building upon our earlier results on the synthesis of electron-precise transition-metal-boron complexes, we continue to investigate the reactivity of pentaborane(9) and tetraborane(10) analogues of ruthenium and rhodium towards thiazolyl and oxazolyl ligands. Thus, mild thermolysis of nido-[(CpRuH)2B3H7] (1) with 2-mercaptobenzothiazole (2-mbtz) and 2-mercaptobenzoxazole (2-mboz) led to the isolation of Cp-based (Cp* = η(5)-C5Me5) borate complexes 5 a,b [CpRuBH3L] (5 a: L = C7H4NS2; 5 b: L = C7H4NOS)) and agostic complexes 7 a,b [CpRuBH2(L)2], (7 a: L = C7H4NS2; 7 b: L = C7H4NOS). In a similar fashion, a rhodium analogue of pentaborane(9), nido-[(CpRh)2B3H7] (2) yielded rhodaboratrane [CpRhBH(L)2], 10 (L = C7H4NS2). Interestingly, when the reaction was performed with an excess of 2-mbtz, it led to the formation of the first structurally characterized N,S-heterocyclic rhodium-carbene complex [(CpRh)(L2)(1-benzothiazol-2-ylidene)] (11) (L = C7H4NS2). Furthermore, to evaluate the scope of this new route, we extended this chemistry towards the diruthenium analogue of tetraborane(10), arachno-[(CpRuCO)2B2H6] (3), in which the metal center possesses different ancillary ligands.
基于我们早期关于电子精确过渡金属硼配合物合成的研究成果，我们继续研究钌和铑的戊硼烷（9）和丁硼烷（10）类似物与噻唑基和恶唑基配体的反应活性。因此，用2-巯基苯并噻唑（2-mbtz）和2-巯基苯并恶唑（2-mboz）对巢式-[(CpRuH)2B3H7]（1）进行温和热解，得到了基于Cp（Cp* = η(5)-C5Me5）的硼酸盐配合物5 a,b [CpRuBH3L]（5 a：L = C7H4NS2；5 b：L = C7H4NOS）和agostic配合物7 a,b [CpRuBH2(L)2]，（7 a：L = C7H4NS2；7 b：L = C7H4NOS）。以类似的方式，戊硼烷（9）的铑类似物，巢式-[(CpRh)2B3H7]（2）生成了铑硼氮杂环丁烷[CpRhBH(L)2]，10（L = C7H4NS2）。有趣的是，当反应使用过量的2-mbtz进行时，导致形成了首个结构表征的N,S-杂环铑卡宾配合物[(CpRh)(L2)(1-苯并噻唑-2-亚基)]（11）（L = C7H4NS2）。此外，为了评估这条新路线的适用范围，我们将这种化学方法扩展到丁硼烷（10）的二钌类似物，蛛网式-[(CpRuCO)2B2H6]（3），其中金属中心具有不同的辅助配体。
