nido-Carborane building-block reagents. 1. Polycyclic arene RR′C2B4H6 derivatives: Synthesis via indenyl and fluorenyl alkynes and metal-promoted oxidative fusion
nido-Carborane building-block reagents. 1. Polycyclic arene RR′C2B4H6 derivatives: Synthesis via indenyl and fluorenyl alkynes and metal-promoted oxidative fusion
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硝基碳硼烷结构单元试剂 1. 多环芳烃 RR′C2B4H6 衍生物：通过茚基和芴基炔烃以及金属促进的氧化融合合成。
DOI：
10.1021/ic00291a006
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发表时间：
1988
影响因子：
4.6
通讯作者：
R. Grimes
中科院分区：
文献类型：
--
作者：
Markus Fessler;J. Spencer;J. F. Lomax;R. Grimes
The preparations of C-mono-and C, C'-bis (indenylmethyl) and C-mono-and C, C'-bis (fluorenylmethyl) derivatives of nido-2, 3-dicarbahexaborane (8)(C2B4H8) are described. These carboranes are multifunctional, presentingseveral aryl and carboranyl sites for metal 1 or 6 coordination, and are designed as structural modules for use in the construction of multiunit metal sandwich complexes and proposed electron-delocalized solid-state arrays. The carborane syntheseswere conducted via the method of Hosmane and Grimes, involving the reaction of alkynes with B5H9 in the presence of (C2H5) 3N. However, these preparations required a priori the syntheses of the first known difluorenyl and diindenyl alkynes, as well as an improved synthesis of (9-fluorenylmethyl) acetylene. In the formation of the bis (indenylmethyl) acetylene from 1-lithioindene, an unexpected 1— 2 rearrangement occurred to give the 2-substituted product exclusively. The new alkynes and carboranes were characterized via multinuclear NMR, IR, and mass spectroscopy, and the properties of the rado-RR'C2B4H6 carboranes toward bridge deprotonation, complexationwith Fe2+, and subsequent fusion to generate R2R'2C4B8H8 products were explored. All of the new RR'C2B4H6 species are deprotonated by NaH in THF to give the RR'C2B4H5~ anions, and the monosubstituted anions (R= indenylmethyl, fluorenylmethyl; R'= H) undergo slow Fe2+-promoted fusion to form R2C4B8H10. However, the disubstituted R2C2B4H5 “anions do not fuse, owing to steric hindrance by the bulky R groups; the diindenyl species forms a complex of the type (R2C2B4H4) Fe (THF) I (x= 2 or 3), which does not react further. Treatment of the neutral diindenyl carboranewith FeCl2 gave in low yield an apparent intramolecular sandwich complex in which the iron is proposed to be^-coordinated to the C5 rings of both indenyl groups.
