4326-29-8Relevant academic research and scientific papers
Decarboxylative cross-nucleophile coupling via ligand-to-metal charge transfer photoexcitation of Cu(ii) carboxylates
Li, Qi Yukki,Gockel, Samuel N.,Lutovsky, Grace A.,DeGlopper, Kimberly S.,Baldwin, Neil J.,Bundesmann, Mark W.,Tucker, Joseph W.,Bagley, Scott W.,Yoon, Tehshik P.
, p. 94 - 99 (2022/01/11)
Reactions that enable carbon–nitrogen, carbon–oxygen and carbon–carbon bond formation lie at the heart of synthetic chemistry. However, substrate prefunctionalization is often needed to effect such transformations without forcing reaction conditions. The development of direct coupling methods for abundant feedstock chemicals is therefore highly desirable for the rapid construction of complex molecular scaffolds. Here we report a copper-mediated, net-oxidative decarboxylative coupling of carboxylic acids with diverse nucleophiles under visible-light irradiation. Preliminary mechanistic studies suggest that the relevant chromophore in this reaction is a Cu(ii) carboxylate species assembled in situ. We propose that visible-light excitation to a ligand-to-metal charge transfer (LMCT) state results in a radical decarboxylation process that initiates the oxidative cross-coupling. The reaction is applicable to a wide variety of coupling partners, including complex drug molecules, suggesting that this strategy for cross-nucleophile coupling would facilitate rapid compound library synthesis for the discovery of new pharmaceutical agents. [Figure not available: see fulltext.].
One-Pot Synthesis of α-Branched N-Acylamines via Titanium-Mediated Condensation of Amides, Aldehydes, and Organometallics
Dai, Chunhui,Genovino, Julien,Bechle, Bruce M.,Corbett, Matthew S.,Huh, Chan Woo,Rose, Colin R.,Sun, Jianmin,Warmus, Joseph S.,Blakemore, David C.
supporting information, p. 1064 - 1067 (2017/03/15)
A three-component, titanium-mediated synthesis of α-branched N-acylamines from commercial or readily accessible amides, aldehydes, and organometallic reagents is reported. The transformation proceeds under mild reaction conditions and tolerates a variety of functional groups (including nitrile, carbamate, olefin, basic amine, furan, and other sensitive heteroaromatics) to generate a large umbrella of α-branched N-acylamine products in high yields. The operationally practical procedure enables the use of this method in parallel chemical synthesis, a valuable feature that can facilitate the screening of bioactive molecules by medicinal chemists.
Microwave-Enhanced Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)imines
Pablo, Oscar,Guijarro, David,Yus, Miguel
, p. 7034 - 7038 (2016/02/19)
Microwave irradiation has considerably enhanced the efficiency of the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)imines in isopropyl alcohol catalyzed by a ruthenium complex bearing the achiral ligand 2-amino-2-methylpropan-1-ol. In addition to shortening reaction times for the transfer hydrogenation processes to only 30 min, the amounts of ruthenium catalyst and isopropyl alcohol can be considerably reduced in comparison with our previous procedure assisted by conventional heating, which diminishes the environmental impact of this new protocol. This methodology can be applied to aromatic, heteroaromatic and aliphatic N-(tert-butylsulfinyl)ketimines, leading, after desulfinylation, to the expected primary amines in excellent yields and with enantiomeric excesses of up to 96 %. Microwave irradiation promotes the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)imines in 2-propanol catalysed by a ruthenium complex bearing an achiral β-amino alcohol as ligand. After desulfinylation, α-branched primary amines containing aromatic, heteroaromatic and aliphatic substituents are obtained in excellent yields and with enantiomeric excesses of up to 96 %.
Aluminum triflate as a powerful catalyst for direct amination of alcohols, including electron-withdrawing group-substituted benzhydrols
Ohshima, Takashi,Ipposhi, Junji,Nakahara, Yasuhito,Shibuya, Ryozo,Mashima, Kazushi
supporting information, p. 2447 - 2452 (2012/11/07)
Direct aminations of allylic alcohols, benzylic alcohols, and benzhydrols with electron-withdrawing (F, Br, I, NO2, or CN) substituents were efficiently catalyzed by aluminum triflate [Al(OTf)3] to afford the corresponding biarylamines in high yield, and the dibromo-substituted product was further transformed into letrozole. Copyright
Solvent-free amination of secondary benzylic alcohols with N-nucleophiles catalyzed by FeCl3
Yu, Jian-Jun,Wang, Li-Min,Guo, Feng-Lou,Liu, Jin-Qian,Liu, Ying,Jiao, Ning
experimental part, p. 1609 - 1616 (2011/06/23)
A general, simple, and environmentally friendly method for the direct amination of secondary benzyl alcohols with amides or 4-nitroaniline is described. This method has been applied to a variety of substrates, and the reaction proceeded smoothly at room temperature under solvent-free conditions. CbzNH2 was proved to be very useful in the direct preparation of the benzylic amines from corresponding alcohols.
Cobalt-catalyzed benzylic C-H amination via dehydrogenative-coupling reaction
Ye, Yang-Hong,Zhang, Ji,Wang, Gao,Chen, Shan-Yong,Yu, Xiao-Qi
supporting information; experimental part, p. 4649 - 4654 (2011/06/27)
An efficient direct benzylic C-H amination via dehydrogenative-coupling by using an inexpensive catalyst/oxidant (CoBr2/tBuOO tBu) system is described. Various unmodified amides including primary or secondary sulfonamides, carboxamides, and carbamates preformed well with benzylic hydrocarbons with moderate to good yields.
Asymmetric synthesis of chiral primary amines by transfer hydrogenation of N -(tert -Butanesulfinyl)ketimines
Guijarro, David,Pablo, Oscar,Yus, Miguel
supporting information; experimental part, p. 5265 - 5270 (2010/10/21)
(Figure presented) The diastereoselective reduction of (R)-N-(tert- butanesulfinyl)ketimines by a ruthenium-catalyzed asymmetric transfer hydrogenation process in isopropyl alcohol, followed by desulfinylation of the nitrogen atom, is an excellent method to prepare highly enantiomerically enriched α-branched primary amines (up to >99% ee) in short reaction times (1-4 h). (1S,2R)-1-Amino-2-indanol has been shown to be a very efficient ligand to perform this transformation. Ketimines bearing either an aryl or a heteroaryl group and an alkyl group as substituents of the iminic carbon atom are very good substrates for this process. The reduction of a dialkyl ketimine could also be achieved, affording the expected amine with moderate optical purity (69% ee). Some amines which are precursors of very interesting biologically and pharmacologically active compounds have been prepared in excellent yields and enantiomeric excesses.
Molecular iodine-catalysed amidation reaction of secondary benzylic and allylic alcohols with carboxamides or sulfonamides
Lin, Xufeng,Wang, Jun,Xu, Fangxi,Wang, Yanguang
experimental part, p. 638 - 641 (2011/03/18)
A highly efficient method for the C-N bond formation via 2 mol% of molecular iodine-catalysed amidation reaction of benzylic and allylic alcohols with carboxamides or sulfonamides in MeCN is described, giving the corresponding substituted amides and allyl
An efficient FeCl3-catalyzed amidation reaction of secondary benzylic and allylic alcohols with carboxamides or p-toluenesulfonamide
Jana, Umasish,Maiti, Sukhendu,Biswas, Srijit
, p. 858 - 862 (2008/04/13)
A simple, inexpensive, environmentally friendly and high yielding amidation reaction of benzylic and allylic alcohols with primary amides using a catalytic amount of FeCl3 (5 mol %) is described. Direct substitution of various amides such as be
Three-component synthesis of amine derivatives using benzylic and allylic alcohols as N-alkylating agents in the absence of external catalysts and additives
Li, Hai-Hua,Dong, De-Jun,Tian, Shi-Kai
experimental part, p. 3623 - 3626 (2009/05/07)
The direct employment of benzylic and allylic alcohols as N-alkylating agents provides a useful synthetic route for amine derivatives by avoiding the preactivation of the hydroxy groups of alcohols. Herein we report a novel by-product-catalyzed three-comp
