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On the Immobilization of a Monophosphaferrocene on a Silica Support
Author(s) -
Komath Mallissery Samith,
Gudat Dietrich
Publication year - 2012
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201200113
Subject(s) - reductive amination , chemistry , derivatization , amination , yield (engineering) , mesoporous material , hydrolysis , alkoxy group , mesoporous silica , homogeneous , condensation reaction , combinatorial chemistry , inorganic chemistry , organic chemistry , catalysis , materials science , high performance liquid chromatography , alkyl , metallurgy , physics , thermodynamics
Reactions of 2‐formyl‐3, 4‐dimethyl‐1‐phosphaferrocene with aminopropyl (AP) functionalized hexagonal mesoporous silica (HMS) were studied in the absence and presence of an excess of the mild reducing agent Na[BH 3 CN]. Starting material and reaction products were characterized by analytical and multinuclear ( 13 C, 29 Si, 31 P) MAS NMR spectroscopic data. Both reactions proceeded by partial derivatization of surface‐bound NH 2 groups to yield products with tethered phosphaferrocene units. Evaluation of spectroscopic data and the results of homogeneous model reactions confirmed that condensation of both components gives imines, which are obviously kinetically labile and allow leakage of the tethered phosphaferrocene into solution. Reactions carried out in the presence of Na[BH 3 CN] proceed as reductive amination to yield secondary amines with enhanced kinetic stability. The reductive amination is accompanied by formation of minor amounts of phosphorus‐containing by‐products as well as the hydrolysis of surface bound ethoxy groups present in the starting material.