84612-77-1Relevant articles and documents
Gold Complexes with ADAP Ligands: Effect of Bulkiness in Catalytic Carbene Transfer Reactions (ADAP = Alkoxydiaminophosphine)
Fructos, Manuel R.,Molina, Francisco,Pérez, Pedro J.,Pizarro, Juan Diego
supporting information, (2020/07/14)
A family of gold(I) complexes of composition AuCl(ADAP) (ADAP = alkoxydiaminophosphine) has been synthetized through a one-pot simple protocol in which the ADAP ligand is prepared in situ before reaction with the Au(I) source. Structural data demonstrate that these ADAP ligands exert a trans effect superior to those of phosphine or phosphite ligands. Evaluation of the buried volume (percentVBur) indicates a steric hindrance higher than those of several NHC, PR3, and P(OR3) ligands, in the context of AuCl(L) complexes. These complexes promote the catalytic transfer of a carbene group from ethyl diazoacetate to alkenes and alkanes. In the case of styrene, both the Csp2-H bonds and the Ca? C bond are functionalized, the relative ratio depending on the catalyst employed and correlating well with the percentVBur value. Data available allow proposing that these compounds display quite similar electronic properties but differ in steric properties, a variable that can be readily controlled upon modifying the alkoxy group at the ADAP ligand by simply replacing the starting alcohol employed in the synthesis.
Improving Catalyst Activity in Hydrocarbon Functionalization by Remote Pyrene–Graphene Stacking
Ballestin, Pilar,Ventura-Espinosa, David,Martín, Santiago,Caballero, Ana,Mata, Jose A.,Pérez, Pedro J.
, p. 9534 - 9539 (2019/06/04)
A copper complex bearing an N-heterocyclic carbene ligand with a pyrene “tail” attached to the backbone has been prepared and supported on reduced graphene oxide (rGO). The free and supported copper materials have been employed as homogeneous and heterogeneous catalysts in the functionalization of hydrocarbons such as n-hexane, cyclohexane, and benzene through incorporation of the CHCO2Et unit from ethyl diazoacetate. The graphene-anchored complex displays higher reaction rates and induces higher yields than its soluble counterpart, features that can be rationalized in terms of a decrease in electron density at the metal center due to a remote net electronic flux from the supported copper complex to the graphene surface.
Water as the Reaction Medium for Intermolecular C-H Alkane Functionalization in Micellar Catalysis
álvarez, María,Gava, Riccardo,Rodríguez, Manuel R.,Rull, Silvia G.,Pérez, Pedro J.
, p. 3707 - 3711 (2017/06/09)
A series of alkanes CnH2n+2 have been functionalized in water as the reaction medium, using a silver-based catalyst, upon the insertion of carbene (CHCO2Et from N2CHCO2Et) groups into the carbon-hydrogen bonds of hexane, cyclohexane, or 2-methylbutane, among others. The regioselectivity toward the distinct reaction sites is identical to that found in neat alkane, the water-based system allowing the use of a much shorter excess of the hydrocarbon. This is the first example of the intermolecular functionalization of alkanes with this strategy in water. The functionalized alkanes partially undergo the incorporation of a second carbene unit to provide α-(acyloxy)acetates, in an unprecedented tandem reaction of this nature.
Functionalization of CnH2n+2 Alkanes: Supercritical Carbon Dioxide Enhances the Reactivity towards Primary Carbon-Hydrogen Bonds
Gava, Riccardo,Olmos, Andrea,Noverges, Bárbara,Varea, Teresa,Funes-Ardoiz, Ignacio,Belderrain, Tomás R.,Caballero, Ana,Maseras, Feliu,Asensio, Gregorio,Pérez, Pedro J.
, p. 3254 - 3260 (2015/10/28)
The functionalization of the primary sites of alkanes is one of the more challenging areas in catalysis. In this context, a novel effect has been discovered that is responsible for an enhancement in the reactivity of the primary C-H bonds of alkanes in a catalytic system. The copper complex Cu(NCMe) (=hydrotris{[3,5-bis(trifluoromethyl)-4-bromo]-pyrazol-1-yl}borate) catalyzes the functionalization of CnH2n+2 with ethyl diazoacetate upon inserting the CHCO2Et unit into C-H bonds. In addition, the selectivity of the reaction toward the primary sites significantly increased relative to that obtained in neat alkane upon using supercritical carbon dioxide as the reaction medium. This was attributed to the effect of the carbon dioxide molecules that withdraw electron density from the fluorine atoms of the ligand, which enhances the electrophilic nature of the metal center. DFT studies validated this proposal.
Functionalization of non-activated C-H bonds of alkanes: An effective and recyclable catalytic system based on fluorinated silver catalysts and solvents
Fuentes, M. Angeles,Munoz, Bianca K.,Jacob, Kane,Vendier, Laure,Caballero, Ana,Etienne, Michel,Perez, Pedro J.
supporting information, p. 1327 - 1334 (2013/03/14)
The complexes Fn-Tp 4Bo,3R fAg(L) (Fn-Tp 4Bo,3R f=a perfluorinated hydrotris(indazolyl) borate ligand; L=acetone or tetrahydrofuran) efficiently catalyze the functionalization of non-activated alkanes such as hexane, 2,3-dimethylbutane, or 2-methylpentane by insertion of CHCO 2Et units (from N2CHCO2Et, ethyl diazoacetate, EDA) into their C-H bonds. The reactions are quantitative (EDA-based), with no byproducts derived from diazo coupling being formed. In the case of hexane, the functionalization of the methyl C-H bonds has been achieved with the highest regioselectivity known to date with this diazo compound. This catalytic system also operates under biphasic conditions by using fluorous solvents such as Fomblin or perfluorophenanthrene. Several cycles of catalyst recovery and reuse have been performed, with identical chemo- and regioselectivities. Copyright
Catalytic hydrocarbon functionalization with gold complexes containing n-heterocyclic carbene ligands with pendant donor groups
Delgado-Rebollo, Manuela,Beltran, Aalvaro,Prieto, Auxiliadora,Mar Diaz-Requejo,Echavarren, Antonio M.,Perez, Pedro J.
experimental part, p. 1380 - 1386 (2012/05/31)
A series of silver and gold complexes bearing N-heterocyclic carbene ligands with a -CH2CO2Et pendant group attached to one N atom of the NHC ligand have been prepared. The catalytic properties of the gold complexes toward the decomposition of ethyl diazoacetate (N2CHCO 2Et) and the transfer of the carbene CHCO2Et group to benzene and hexane have been investigated. A somewhat different reaction outcome has been found for this family of gold catalysts compared with the parent IPrAuCl catalyst. Gold-based catalysts containing NHC ligands with potentially coordinating pendant groups have been tested in the functionalization of Caspa2-H and Caspa3-H bonds by carbene insertion from ethyl diazoacetate, showing moderate catalytic activity.
Intermetallic coinage metal-catalyzed functionalization of alkanes with ethyl diazoacetate: Gold as a ligand
Fuentes, M. ángeles,Rodríguez-Castillo, María,Monge, Miguel,Olmos, M. Elena,López-De-Luzuriaga, Jose M.,Caballero, Ana,Pérez, Pedro J.
experimental part, p. 146 - 149 (2011/06/22)
The complexes [Au2M2(C6F5) 4(NCMe)2]n (M = Cu, 1; M = Ag, 2) have been tested as catalysts for the functionalization of alkanes by the carbene insertion methodology, using ethyl diazoacetate as the carbene source. Moderate to high conversions have been obtained. The observed selectivities seem to favor the proposal that the active metal for catalysis is the Cu/Ag center, the Au(C6F5)2 unit acting as a spectator ligand in both cases.
Highly selective metal catalysts for intermolecular carbenoid insertion into primary C-H bonds and enantioselective C-C bond formation
Thu, Hung-Yat,Tong, Glenna So-Ming,Huang, Jie-Sheng,Chan, Sharon Lai-Fung,Deng, Qing-Hai,Che, Chi-Ming
supporting information; scheme or table, p. 9747 - 9751 (2009/05/30)
(Figure Presented) Primary C-H bond activation! A Rh complex of bis-pocket porphyrin I catalyzes carbenoid insertion into the C-H bonds of n-alkanes with a primary/secondary selectivity (per C-H bond) of up to 11.4:1 (see picture). Enantioselective secondary C-H bond functionalization catalyzed by a Rh complex of Halterman's chiral porphyrin features up to 93% ee. These reactions exhibit up to 6477 turnovers after the catalyst was recycled five times.
HOMOLOGATION OF N-ALKANES USING DIAZOESTERS AND RHODIUM(III)PORPHYRINS. ENHANCED ATTACK ON PRIMARY C-H BONDS.
Callot, H.J.,Metz, F.
, p. 4321 - 4324 (2007/10/02)
Carbethoxycarbene, from ethyl diazoacetate and rhodium(III)porphyrins, inserted into methyl C-H bonds of n-alkenes (C6 to C12) with yields up to 20-25 percent corresponding to a large increase of the primary/secondary selectivity.