Synthesis and crystal structures of [Rh(TTP)(CH3)]2(μ-CNpy) and [Rh(TTP)(C8H11)] (TTP=5,10,15,20-tetra(p-tolyl)porphyrin dianion; CNpy=4-cyanopyridine; C8H11=(5-norbornen-2-yl)methyl)
摘要:
Interaction of [Rh(TPP)CH3] (TTP = 5,10,1 5,20-tetra(p-tolyl)porphyrin dianion) with bidentate ligands L affords [Rh(TTP)CH3](2)(mu-L) (L = 4-cyanopyridine (1) or 4,4'-bipyridine (2)). The structure of 1 has been established by X-ray crystallography. The average Rh-C, average Rh-N(pyrrole), and average Rh-N(CNpy) distances in 1 are 2.032(4), 2.032, and 2.273(4) A, respectively. The reaction of Na[Rh(TTP)] with (5-norbornen-2-yl)methyl iodide (C8H11I) affords [Rh(TTP)(C8H11)] (5), which has been characterized by X-ray diffraction study. The Rh-C and average Rh-N distance in 5 are 2.052(6) and 2.022 Angstrom, respectively. (C) 2000 Elsevier Science S.A. All rights reserved.
Identification of the active catalyst in the rhodium porphyrin-mediated cyclopropanation of alkenes
作者:David W. Bartley、Thomas Kodadek
DOI:10.1021/ja00058a007
日期:1993.3
cyclopropanation of alkenes by diazo esters. Mechanistic studies of this reaction have resulted in the spectroscopic characterization of several potential organometallic intermediates in the reaction, including a novel metal diazonium complex resulting from alkylation of the rhodium center by ethyl diazoacetate. This compound is thought to decompose to a metal carbene that subsquently transfers the carbene fragment