7717-61-5Relevant academic research and scientific papers
Size-Induced Inversion of Selectivity in the Acylation of 1,2-Diols
Mayr, Stefanie,Zipse, Hendrik
, p. 18084 - 18092 (2021/12/02)
Relative rates for the Lewis base-catalyzed acylation of aryl-substituted 1,2-diols with anhydrides differing in size have been determined by turnover-limited competition experiments and absolute kinetics measurements. Depending on the structure of the anhydride reagent, the secondary hydroxyl group of the 1,2-diol reacts faster than the primary one. This preference towards the secondary hydroxyl group is boosted in the second acylation step from the monoesters to the diester through size and additional steric effects. In absolute terms the first acylation step is found to be up to 35 times faster than the second one for the primary alcohols due to neighboring group effects.
Geminal difunctionalization of vinylarenes: Concise synthesis of 1,3-dioxolan-4-ones
Balaji, Pandur Venkatesan,Chandrasekaran, Srinivasan
supporting information, p. 2263 - 2267 (2019/12/11)
We report a straightforward method for the synthesis of five-membered 1,3-dioxolan-4-ones by an unprecedented oxidative alkene geminal difunctionalization strategy using α-hydroxy carboxylic acids. Under the geminal oxidative addition conditions, various substituted α-hydroxy carboxylic acids and styrenes containing a variety of substituents, including β-substituted styrenes, were effectively coupled regioselectively (anti-Markovnikov) with an isobutyl-substituted chiral α-hydroxy carboxylic acid, providing an annulation with excellent dia?-?-stereoselectivity. An aryl migration in the semipinacol rearrangement leading to geminal oxidative addition of the α-hydroxy carboxylic acids was confirmed by deuterium-labelling and control studies.
Regioselective benzoylation of diols and carbohydrates by catalytic amounts of organobase
Lu, Yuchao,Hou, Chenxi,Ren, Jingli,Xin, Xiaoting,Xu, Hengfu,Pei, Yuxin,Dong, Hai,Pei, Zhichao
, (2016/07/06)
A novel metal-free organobase-catalyzed regioselective benzoylation of diols and carbohydrates has been developed. Treatment of diol and carbohydrate substrates with 1.1 equiv. of 1-benzoylimidazole and 0.2 equiv. of 1,8-diazabicyclo[5.4.0]undec-7-ene (DB
A green and convenient method for regioselective mono and multiple benzoylation of diols and polyols
Zhang, Xiaoling,Ren, Bo,Ge, Jiantao,Pei, Zhichao,Dong, Hai
, p. 1005 - 1010 (2016/02/03)
An efficient method for regioselective benzoylation of diols and polyols was developed. The benzoylation is catalyzed by only 0.2 equiv of benzoate anion in acetonitrile with the addition of a stoichiometric amount of benzoic anhydride under very mild condition, leading to high yields. Compared with all other methods, this method shows particular advantage in regioselective multiple benzoylation of polyols, and in avoiding the use of any metal-based catalysts and any amine bases, which is more environment-friendly.
Alkene Oxyalkylation Enabled by Merging Rhenium Catalysis with Hypervalent Iodine(III) Reagents via Decarboxylation
Wang, Yin,Zhang, Lei,Yang, Yunhui,Zhang, Ping,Du, Zhenting,Wang, Congyang
supporting information, p. 18048 - 18051 (2014/01/06)
Rhenium-catalyzed oxyalkylation of alkenes is described, where hypervalent iodine(III) reagents derived from widely occurring aliphatic carboxylic acids were used as, for the first time, not only an oxygenation source but also an alkylation source via decarboxylation. The reaction also features a wide substrate scope, totally regiospecific difunctionalization, mild reaction conditions, and ready availability of both substrates. Mechanistic studies revealed a decarboxylation/radical-addition/cation-trapping cascade operating in the reaction.
N-acyl 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) tetraphenylborate salts as O-acylating agents
Taylor, James E.,Williams, Jonathan M.J.,Bull, Steven D.
experimental part, p. 4074 - 4076 (2012/08/28)
Air-stable and crystalline N-acyl DBN tetraphenylborate salts have been shown to be effective O-acylating agents, reacting with both primary and secondary alcohols to give the corresponding esters in good yields. In the case of diols, the N-acyl DBN·BPh4 salts have been shown to acylate regioselectively the primary alcohol functionality in the presence of a secondary alcohol. The DBN hydrotetraphenylborate side product can be readily removed by filtration, providing the ester products without the need for further purification.
Organotin-Mediated Monoacylation of Diols with Reversed Chemoselectivity: A Convenient Synthetic Method
Reginato, Gianna,Ricci, Alfredo,Roelens, Stefano,Scapecchi, Serena
, p. 5132 - 5139 (2007/10/02)
The organotin-mediated monoesterification of unsymmetrical diols with reversed chemoselectivity has been explored to ascertain scope and limits of the method and to provide an easy and convenient synthetic procedure.The reaction has been performed on a set of substituted diols with some acylating agents usually employed as protecting groups.Two different procedures have been devised to obtain either the desired diol monoesters directly or the corresponding trialkylsilyl ethers as protected derivatives.The latter provides a convenient approach to the preparation of easily interconvertible diol monoesters.Also, the reaction has been optimized as a one-pot procedure, avoiding the isolation and purification of the stannylated intermediates.The reversed monoesterification method has been successfully applied to 1,2-, 1,3-, and 1,4-diols of primary-secondary, primary-tertiary, and secondary-tertiary types and to ether functions containing 1,2-diols.Within its limits, the described method represents the first direct one-pot monoesterification of diols at the most substituted site, allowing some remarkable achievements as (a) an almost regiospecific reversed monobenzoylation of some 1,2-diols, (b) the selective acylation of the tertiary hydroxyl of a primary-tertiary diol, and (c) a highly selective preparation of secondary pivalate of primary-secondary diols.
Studies on the Synthesis of Heterocyclic Compounds. VII. Action of Acyl Halides on Heterocyclic Compounds Containing the O-M-O (M = P, As, Sb) Bond in the Ring
Anchisi, Carlo,Corda, Luciana,Maccioni, Antonio,Podda, Gianni
, p. 141 - 144 (2007/10/02)
The action of acyl halides on heterocyclic compounds of five-membered rings containing an O-M-O (M = P, As, Sb) linkage is described.The reactions were either carried out in the presence of a solvent (benzene or toluene) or by direct heating of the reagent with the substrate.In the case of arsole, stibole and stannole derivatives, the cleavage of O-M bond and the formation of the respective mono- and diesters were always obtained, while with the phospholes, no cleavage of the compounds was observed.The products IIa-c (M = Sb) have been obtained in excellent yields starting from VIa-c and antimony trichloride.The structure of the compounds which were prepared was determined by analytical and spectroscopic methods and also by comparations with authentic samples where possible.
DIALKYL ACYLPHOSPHONATES: A NEW ACYLATING AGENT OF ALCOHOLS
Sekine, Mitsuo,Kume, Akiko,Hata, Tsujiaki
, p. 3617 - 3620 (2007/10/02)
Diethyl benzoylphosphonate (1) underwent facile benzoylation of alcohols in the presence of DBU.Reactions of diols containing primary and secondary hydroxyl groups with 1 gave predominantly monobenzoates in which primary hydroxyl groups were highly selectively benzoylated.Related acylations were also described.
