Balbo-Block M, Bartel C, Lentz D, Preugschat D
Fachbereich Chemie, Institut für Chemie-Anorganische und Analytische Chemie Freie Universität Berlin, Germany.
Chemistry. 2001;7(4):881-93. doi: 10.1002/1521-3765(20010216)7:4<881::aid-chem881>3.0.co;2-2.
The radical alkylation of tetraethylammonium pentacarbonyl(cyano)chromate 1 yielded the halogenated ethyl isocyanide complexes [(CO)5Cr(CN-CClX-CClYF)] 3 (a, X= Cl, Y= F; b, X = F, Y= F and c, X=Y= Cl). Dehalogenation of 3 using zinc in diethyl ether gave [(CO)5Cr(CN-CX=CFY)] 4. The compounds 4a, b reacted with various nucleophiles exclusively at the difluoromethylene group. The unstable phosphorane 5, which is formed on reaction of 4b with trimethylphosphane, decomposed thermally and on hydrolysis yielding pentacarbonyl(1,2-difluoroethenyl isocyanide)chromium (6). The cyano substituent can be introduced in the beta position of the isocyanide function by reaction of 4a, b with potassium cyanide, leading to the formation of [(CO)5Cr(CN-CX=CF-CN)] (7). Reactions of 4a, b with organolithium or organomagnesium compounds yielded [(CO)5Cr(CN-CX=CF-R)] (8) and [(CO)5Cr(CN-CF=CF-C...C-CF=CF-NC)Cr(CO)5] (10). The trimethylsilyl group in 8a, b, d could be removed by a solution of potassium carbonate in methanol leading to [(CO)5Cr(CN-CX=CF-Cn-H)] (11) (n=2,4). Octacarbonyldicobalt reacted with 8e under coordination of the C-C triple bond to the hexacarbonyldicobalt fragment, resulting in the cluster compound 12. The crystal and molecular structure of 8i, 11 a, b, and 12 were elucidated by X-ray crystallography. The alkenyl and alkynyl isocyanides CN-CCl=CF2 (13a), CN-CF=CF2 (13b), CN-CCl=CClF (13c), CN-CF=CFH (14), CN-CC-H (15), CN-CC-CN (16), and CN-CCl=CF-CN (17) were obtained by flash vacuum pyrolysis of 4a, 4b, 4c, 6, and 7a, respectively.
五羰基（氰基）铬酸四乙铵1的自由基烷基化反应生成了卤代乙基异腈配合物[(CO)5Cr(CN - CClX - CClYF)] 3（a，X = Cl，Y = F；b，X = F，Y = F；c，X = Y = Cl）。在二乙醚中用锌对3进行脱卤反应得到[(CO)5Cr(CN - CX=CFY)] 4。化合物4a、b仅在二氟亚甲基处与各种亲核试剂发生反应。4b与三甲基膦反应生成的不稳定磷叶立德5会发生热分解，水解时生成五羰基（1,2 - 二氟乙烯基异腈）铬（6）。4a、b与氰化钾反应可将氰基引入异腈官能团的β位，生成[(CO)5Cr(CN - CX=CF - CN)]（7）。4a、b与有机锂或有机镁化合物反应生成[(CO)5Cr(CN - CX=CF - R)]（8）和[(CO)5Cr(CN - CF=CF - C...C - CF=CF - NC)Cr(CO)5]（10）。8a、b、d中的三甲基硅基可通过碳酸钾的甲醇溶液除去，得到[(CO)5Cr(CN - CX=CF - Cn - H)]（11）（n = 2,4）。八羰基二钴与8e反应，C - C三键与六羰基二钴片段配位，生成簇合物12。通过X射线晶体学确定了8i、11a、b和12的晶体和分子结构。分别通过对4a、4b、4c、6和7a进行快速真空热解得到烯基和炔基异腈CN - CCl=CF2（13a）、CN - CF=CF2（13b）、CN - CCl=CClF（13c）、CN - CF=CFH（14）、CN - CC - H（15）、CN - CC - CN（16）和CN - CCl=CF - CN（17）。
