35583-33-6Relevant academic research and scientific papers
Some Observations on the Mechanism of Diorganocuprate 1,4-Addition Reactions with α,β-Unsaturated Ketones: Effects of Diethyl Ether in Reactions of Butylcoppers in Toluene
Kingsbury, Celia L.,Smith, Robin A.J.
, p. 4629 - 4634 (1997)
Mixtures of butyllithium and copper iodide prepared in toluene react with α,β-unsaturated ketones predominantly in a 1,2-fashion. Addition of 2 equiv of diethyl ether to the system results in a dramatic preference for the 1,4-product, as found normally with diorganocuprates in ethereal solvents. These results are in accordance with the theoretical predictions that a suitable ligand is required to facilitate the stabilization of a formally copper(III) reaction intermediate on the 1,4-addition mechanistic pathway.
Palladium-catalyzed site-selective arylation of aliphatic ketones enabled by a transient ligand
Pan, Lei,Yang, Ke,Li, Guigen,Ge, Haibo
supporting information, p. 2759 - 2762 (2018/03/21)
Transition metal-catalyzed direct C-H bond functionalization enabled by transient ligands has become an attractive topic. Here we report a palladium-catalyzed site-selective arylation of β-C(sp3)-H bonds in aliphatic ketones with β-alanine as the transient ligand.
CuCl/bipyridine-catalyzed addition reactions of arylboroxines with aldehydes, α,β-unsaturated ketones, and N-tosyl aldimines
Liao, Yuan-Xi,Hu, Qiao-Sheng
experimental part, p. 7602 - 7607 (2011/11/12)
CuCl/bipyridine-catalyzed addition reactions of arylboroxines with aldehydes and α,β-unsaturated ketones at elevated temperatures were described. By using the microwave energy, CuCl/bipyridine-catalyzed addition reactions of arylboroxines with aldimines were also realized.
Enders SAMP-hydrazone as traceless auxiliary in the asymmetric 1,4-addition of cuprates to enones
Sammet, Karsten,Gastl, Christoph,Baro, Angelika,Laschat, Sabine,Fischer, Peter,Fettig, Ina
supporting information; experimental part, p. 2281 - 2290 (2010/12/29)
Conjugate additions of Gilman cyanocuprates to (5)-N-amino-2- (methoxymethyl)pyrrolidine (SAMP)-hydrazones 4, 5 derived from cyclic and acyclic α,β-unsaturated ketones were investigated. A protocol utilizing copper(II) sulfate/ammonium chloride was evolved, which allowed cleavage of SAMP (S)-1 under the hydrolysis and work-up conditions, followed by recovery of the auxiliary with ethylenediaminetetraacetic acid (EDTA). The enantioselectivity of cuprate additions was dominated for cyclic SAMP-hydrazones 4 by the cuprate alkyl substituent and the ring size, in the case of acyclic arylidene SAMP-hydrazones 5, however, by the nature of the aryl substituent. Electron-donating substituents gave poor enantiomeric excesses, whereas electron-withdrawing groups provided excellent ee values of 98-99%. The configuration of the new stereocenter was determined to be (R). Moreover, a reaction sequence was developed which integrates a tandem 1,4-addition/ methylation and traceless hydrolytic cleavage of the auxiliary (S)-1 in a one-pot reaction, resulting in enantiomerically pure methyl ketones 11-13, each of them with > 99% ee.
Orthoplatinated triarylphosphite as a highly efficient catalyst for addition reactions of arylboronic acids with aldehydes: Low catalyst loading catalysis and a new tandem reaction sequence
Liao, Yuan-Xi,Xing, Chun-Hui,He, Ping,Hu, Qiao-Sheng
supporting information; experimental part, p. 2509 - 2512 (2009/05/26)
(Chemical Equation Presented) Readily available, air/moisture-stable orthoplatinated triarylphosphite catalyzes the addition reactions of arylboronic acids with aldehydes with the catalyst loading as low as 0.01%. It also cataylzes a new tandem reaction of arylboronic acids with α,β- unsaturated aldehydes to form 1,3-diaryl-1-propanols. Our study provides a new paradigm for the application of orthoplatinated triarylphosphites, and may pave the road to develop other Pt(II) catalysts for such addition reactions and other tandem reactions with such addition reactions as part of the reaction sequence.
Synthesis of β-aryl ketones by tetraphosphine/palladium catalysed Heck reactions of 2- or 3-substituted allylic alcohols with aryl bromides
Berthiol, Florian,Doucet, Henri,Santelli, Maurice
, p. 4372 - 4383 (2007/10/03)
Through the use of [PdCl(C3H5)]2/cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of aryl bromides undergoes Heck reaction using 2- or 3-subtituted allylic alcohols. With these sterically congested alkenes, the selective formation of β-aryl ketones was observed when appropriate reaction conditions were used. The influence of the functional group on the aryl bromide and of the base on the selectivity is remarkable. With several substrates, much higher selectivities were obtained using NaHCO3 instead of K2CO3 as base. Furthermore, this catalyst can be used at low loading with several substrates.
Palladium-catalyzed enantioselective conjugate addition of arylboronic acids
Gini, Francesca,Hessen, Bart,Minnaard, Adriaan J.
, p. 5309 - 5312 (2007/10/03)
(Chemical Equation Presented) The first asymmetric palladium-catalyzed conjugate addition of arylboronic acids to α,β-unsaturated aldehydes, ketones, and esters is described. For cyclic substrates, excellent chemo-, regio-, and enantioselectivities are achieved when a Pd(O2CCF 3)2/DuPHOS catalyst is applied.
Enantioselective conjugate addition of diethylzinc to enones with chiral copper-QUIPHOS catalyst influence of the addition of water on the enantioselectivity
Delapierre, Guillaume,Constantieux, Thierry,Brunel, Jean Michel,Buono, Gerard
, p. 2507 - 2511 (2007/10/03)
The use of a new chiral copper catalyst involving QUIPHOS as ligand in the 1,4-addition of Et2Zn to enones is reported. The dramatic beneficial effect of addition of water or Zn(OH)2 to this system has been investigated, and led to a
Novel tridentate diamino organomanganese(II) complexes as homogeneous catalysts in manganese(II)/copper(I) catalyzed carbon-carbon bond forming reactions
Donkervoort, Johannes G.,Vicario, Jose L.,Jastrzebski, Johann T.B.H.,Gossage, Robert A.,Cahiez, Gerard,Van Koten, Gerard
, p. 61 - 69 (2007/10/03)
The new, paramagnetic arylmanganese(II) complex Li[MnCl2(NCN)] (2, NCN [C6H3(CH2NMe2)2-2,6] -) has been obtained in high yield from the reaction of MnCl2 and [Li(NCN)]2 in a 2:1 molar ratio. In THF solution, 2 is likely an ionic species [Li(THF)n] [MnCl2(NCN)] (molecular weight determination and conductivity measurements), while magnetic measurements indicate that a high spin d5 manganese(II) center is present. Subsequent reaction of 2 with RLi afforded [MnR(NCN)] (R=Me (3a), n-Bu (3b)). Complex 2, using CuCl as a co-catalyst, is an effective catalyst system for cross-coupling of Grignard reagents with alkyl bromides and the 1,4-addition of organomagnesium halides to α,β-unsaturated ketones. No further additives or co-solvents are necessary. For both reactions a dramatic decrease in reaction times is observed when compared to standard manganese/copper systems. Alkyl bromides with unsaturated or heteroatom functionalities can be cross-coupled. Also, excellent reactivity towards normally unreactive β,β-disubstituted ketones has been observed in the 1,4-addition reaction.
Chiral copper amine complexes
-
, (2008/06/13)
Disclosed herein is a class of chiral copper-amine complexes of the formula R(L*) CuLi in which L* is selected from: STR1 In this formula, R is a transferable ligand, which can be alkyl, aryl or aralkyl. M is a metal ion such as Li, Na, K, Cs, Rb, Be, Mg
