2915-72-2Relevant academic research and scientific papers
A facile and versatile electro-reductive system for hydrodefunctionalization under ambient conditions
Huang, Binbin,Guo, Lin,Xia, Wujiong
supporting information, p. 2095 - 2103 (2021/03/26)
A general electrochemical system for reductive hydrodefunctionalization is described, employing the inexpensive and easily available triethylamine (Et3N) as a sacrificial reductant. This protocol is characterized by facile operation, sustainable conditions, and exceptionally wide substrate scope covering the cleavage of C-halogen, N-S, N-C, O-S, O-C, C-C and C-N bonds. Notably, the selectivity and capability of reduction can be conveniently switched by simple incorporation or removal of an alcohol as a co-solvent.
LiHMDS: Facile, highly efficient and metal-free transesterification under solvent-free condition
Gore, Kiran R.,Mittapelli, Lavanya L.
, (2020/10/27)
Transesterification is one of the important organic reactions employed in numerous industrial as well as laboratory applications for the synthesis of various esters. Herein, we report a rapid, highly efficient, and transition metal-free transesterification reaction in the presence of LiHMDS under solvent-free conditions. The transesterification reaction was carried out with three different benzoate esters and a wide range of primary and secondary alcohols (from C3-C18) in good to excellent yields (45 examples). By considering the commercial role of esters, this method will be promising for the facile synthesis of esters in industry-relevant applications.
Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
Huang, Changyu,Li, Jinpeng,Wang, Jiaquan,Zheng, Qingshu,Li, Zhenhua,Tu, Tao
, p. 66 - 71 (2020/11/18)
The amide C-N cleavage has drawn a broad interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments, density functional theory (DFT) calculations and kinetic studies. Besides broad substrate scopes and excellent functional groups tolerance, this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C-N bonds for organic synthesis and pharmaceutical industry. [Figure not available: see fulltext.]
Electrochemical esterification via oxidative coupling of aldehydes and alcohols
Smeyne, Dylan,Verboom, Katherine,Bryan, Maria,LoBue, James,Shaikh, Abid
supporting information, (2021/03/26)
An electrolytic method for the direct oxidative coupling of aldehydes with alcohols to produce esters is described. Our method involves anodic oxidation in presence of TBAF as supporting electrolyte in an undivided electrochemical cell equipped with graphite electrodes. This method successfully couples a wide range of alcohols to benzaldehydes with yields ranging from 70 to 90%. The protocol is easy to perform at a constant voltage conditions and offers a sustainable alternative over conventional methods.
Cesium Carbonate Catalyzed Esterification of N-Benzyl- N-Boc-amides under Ambient Conditions
Ye, Danfeng,Liu, Zhiyuan,Chen, Hao,Sessler, Jonathan L.,Lei, Chuanhu
supporting information, p. 6888 - 6892 (2019/09/07)
We report a general activated amide to ester transformation catalyzed by Cs2CO3. Using this approach, esterification proceeds under relatively mild conditions and without the need for a transition metal catalyst. This method exhibits broad substrate scope and represents a practical alternative to existing esterification strategies. The synthetic utility of this protocol is demonstrated via the facile synthesis of crown ether derivatives and the late-stage modification of a representative natural product and several sugars in reasonable yields.
Silver-mediated oxidative functionalization of alkylsilanes
Wang, Feng,Xu, Peng,Cong, Fei,Tang, Pingping
, p. 8836 - 8841 (2019/01/03)
A general approach to the functionalization of aliphatic C-Si bonds in the presence of silver salts and oxidants has been reported. This strategy encompasses a range of valuable C-Si transformations, including the direct conversions of a C-Si bond to C-OCF3, C-OBz, C-OCOCF3, C-SCF3, C-SCN, and C-N3 bonds. Among them, trifluoromethoxylation of alkylsilanes is reported for the first time. In addition, mechanistic studies indicate that this reaction may proceed through a radical mechanism.
Integrative Photoreduction of CO2 with Subsequent Carbonylation: Photocatalysis for Reductive Functionalization of CO2
He, Xing,Cao, Yu,Lang, Xian-Dong,Wang, Ning,He, Liang-Nian
, p. 3382 - 3387 (2018/09/14)
Efficient conversion of CO2 into fuels and chemicals with solar energy would be promising, but also faces great challenge. In this context, we describe the photoreductive functionalization of CO2 to construct new C?C, C?N, and C?O bonds through the respective Pd-catalyzed Suzuki carbonylation, aminocarbonylation, and alkoxycarbonylation of aryl iodides with CO in situ generated through the photoreduction of CO2. This protocol opens up an alternative avenue for CO2 utilization by harnessing solar energy.
Nucleophilic Substitutions of Alcohols in High Levels of Catalytic Efficiency
Stach, Tanja,Dr?ger, Julia,Huy, Peter H.
supporting information, p. 2980 - 2983 (2018/05/28)
A practical method for the nucleophilic substitution (SN) of alcohols furnishing alkyl chlorides, bromides, and iodides under stereochemical inversion in high catalytic efficacy is introduced. The fusion of diethylcyclopropenone as a simple Lewis base organocatalyst and benzoyl chloride as a reagent allows notable turnover numbers up to 100. Moreover, the use of plain acetyl chloride as a stoichiometric promotor in an invertive SN-type transformation is demonstrated for the first time. The operationally straightforward protocol exhibits high levels of stereoselectivity and scalability and tolerates a variety of functional groups.
Systematic Evaluation of Sulfoxides as Catalysts in Nucleophilic Substitutions of Alcohols
Motsch, Sebastian,Schütz, Christian,Huy, Peter H.
supporting information, p. 4541 - 4547 (2018/09/13)
Herein, a method for the nucleophilic substitution (SN) of benzyl alcohols yielding chloro alkanes is introduced that relies on aromatic sulfoxides as Lewis base catalysts (down to 1.5 mol-%) and benzoyl chloride (BzCl) as reagent. A systematic screening of various sulfoxides and other sulfinyl containing Lewis bases afforded (2-methoxyphenyl)methyl sulfoxide as optimal catalyst. In contrast to reported formamide catalysts, sulfoxides also enable the application of plain acetyl chloride (AcCl) as reagent. In addition, it was demonstrated that weakly electrophilic carboxylic acid chlorides like BzCl promote Pummerer rearrangement of sulfoxides already at room temperature. This side-reaction also provided the explanation, why sulfoxide catalyzed SN-reactions of alcohols do not allow the effective production of aliphatic and electron deficient chloro alkanes. Comparison experiments provided further insight into the reaction mechanism.
Highly Efficient Carbon Monoxide Capture by Carbanion-Functionalized Ionic Liquids through C-Site Interactions
Tao, Duan-Jian,Chen, Feng-Feng,Tian, Zi-Qi,Huang, Kuan,Mahurin, Shannon M.,Jiang, De-En,Dai, Sheng
supporting information, p. 6843 - 6847 (2017/06/06)
A novel method for the highly efficient and reversible capture of CO in carbanion-functionalized ionic liquids (ILs) by a C-site interaction is reported. Because of its supernucleophilicity, the carbanion in ILs could absorb CO efficiently. As a result, a relatively high absorption capacity for CO (up to 0.046 mol mol?1) was achieved under ambient conditions, compared with CO solubility in a commonly used IL [Bmim][Tf2N] (2×10?3 mol mol?1). The results of quantum mechanical calculations and spectroscopic investigation confirmed that the chemical interaction between the C-site in the carbanion and CO resulted in the superior CO absorption capacities. Furthermore, the subsequent conversion of captured CO into valuable chemicals with good reactivity was also realized through the alkoxycarbonylation reaction under mild conditions. Highly efficient CO absorption by carbanion-functionalized ILs provides a new way of separating and converting CO.
