99511-02-1Relevant academic research and scientific papers
Reaction of trihaloisocyanuric acids with alkynes: An efficient methodology for the preparation of β-haloenol acetates
Crespo, Livia T.C.,Nogueira, Geisa P.,De Mattos, Marcio C.S.,Esteves, Pierre M.
, p. 205 - 214 (2018/02/07)
The reaction between trihaloisocyanuric acids and alkynes in the presence of acetic acid provides an efficient methodology for preparation of β-haloenol acetates in yields ranging from 34 to 94%, depending on the halogen and alkynes used. This methodology provides an alternative to typical procedures, which usually employ metal catalysis and are limited to terminal alkynes.
A highly efficient synthesis of 2,5-disubstituted furans from enyne acetates catalyzed by lewis acid and palladium
Chen, Zheng-Wang,Luo, Miao-Ting,Wen, Yue-Lu,Ye, Min,Zhou, Zhong-Gao,Liu, Liang-Xian
supporting information, p. 2341 - 2344 (2015/08/06)
A highly efficient synthesis of a wide range of 2,5-disubstituted furans from enyne acetates is described. The reactions are conducted by using Lewis acid and palladium catalyst and provide symmetrical and unsymmetrical products in good to excellent yields, with broad substrate scope, including a variety of aromatic and aliphatic substituents in the 2- and 5-position of the furan ring.
Selective oxygenation of alkynes: A direct approach to diketones and vinyl acetate
Xia, Xiao-Feng,Gu, Zhen,Liu, Wentao,Wang, Ningning,Wang, Haijun,Xia, Yongmei,Gao, Haiyan,Liu, Xiang
supporting information, p. 9909 - 9913 (2015/01/09)
Arylalkynes can be converted into α-diketones with the use of a copper catalyst, and also be transformed into vinyl acetates under metal-free conditions, both in the presence of PhI(OAc)2 as an oxidant at room temperature. A series of substituted α-diketones were prepared in moderate to good yields. A variety of vinyl halides could be regio- and stereo-selectively synthesized under mild conditions, and I, Br and Cl could be all easily embedded into the alkynes. This journal is
Catalyst-and metal-free rapid functionalizations of alkynes using TsNBr2
Chawla, Ruchi,Singh, Atulk.,Yadav, Laldhar S.
, p. 1558 - 1562 (2013/08/23)
A very rapid (3-12 min) and efficient method has been developed for a one-pot synthesis of α,α-dibromoalkanones and β-bromoenol alkanoates directly from alkynes using N,N-dibromo-p-toluenesulfonamide (TsNBr2). The protocol is embellished with f
Silver-catalyzed difunctionalization of terminal alkynes: Highly regio- and stereoselective synthesis of (Z)-β-Haloenol acetates
Chen, Zhengwang,Li, Jinghao,Jiang, Huanfeng,Zhu, Shifa,Li, Yibiao,Qi, Chaorong
scheme or table, p. 3262 - 3265 (2010/10/02)
(Figure Presented) A new silver-catalyzed highly regio- and stereoselective difunctionalization reaction of simple terminal alkynes was reported in which the (Z)-β-haloenol acetate derivatives were formed efficiently. The resulting products were versatile intermediates in organic synthesis.
Ester Homologation Revisited: A Reliable, Higher Yielding and Better Understood Procedure
Kowalski, Conrad J.,Reddy, Rajarathnam E.
, p. 7194 - 7208 (2007/10/02)
Enolate anions 3 and 6, prepared via enolization of α-bromo and dibromo ketones 4 and 5 were converted in high yield to ynolate anions 10 by respective addition of lithium tetramethylpiperidide (to effect deprotonation, 3 --> 7) or butyllithium (to effect metal-halogen exchange, 6 --> 7).Mixtures of such enolates were also obtainable from esters 1 on a large-scale (25 mmol) via in situ formation and addition of lithiodibromomethane (from methylene bromide and lithium tetramethylpiperidide), followed by treatment of the resulting adducts with lithiumhexamethyldisilazide to ensure complete enolization.Addition of sec-butyllithium and n-butyllithium to effect ynolate anion formation, followed by quenching of the reaction mixtures into acidic ethanol, reproducibly afforded homologated esters 8 in 67-90percent yield.Demonstrated for ethyl esters 1 having the carbethoxy moiety attached to primary, secondary, tertiary, aryl, and alkenyl groups, this general procedure provides a convenient, large-scale alternative to the classical Arndt-Eistert sequence.
Bromomethyl Ketones and Enolates: Alternative Products from Ester Homologation Reactions
Kowalski, Conrad J.,Haque, M. Serajul
, p. 5140 - 5142 (2007/10/02)
Esters 1, in which R represents a primary alkyl, alkynyl, alkenyl, or aromatic substituent, were reacted with (dibromomethyl)lithium, followed by n-butyllithium.Bromomethyl ketone enolate anions 5 resulted, which were quenched with acid to afford bromomethyl ketones 4, generally in 70-85percent yields.Alternatively, enolate anions 5 could be quenched with acetic anhydride to afford bromo enol acetates 7 or treated with tert-butyllithium to produce α-keto dianions 8.
