24744-96-5Relevant articles and documents
Low-valent Tantalum-mediated Reaction
Aoyagi, Yutaka,Tanaka, Wataru,Ohta, Akihiro
, p. 1225 - 1226 (1994)
Treatment of a mixture of α-halogeno-esters and carbonyl compounds with low valent tantalum prepared readily from tantalum(V) chloride and activated zinc, afforded β-hydroxy esters in moderate to good yields.
A Ball-Milling-Enabled Reformatsky Reaction
Cao, Qun,Stark, Roderick T.,Fallis, Ian A.,Browne, Duncan L.
, p. 2554 - 2557 (2019/06/17)
An operationally simple one-jar one-step mechanochemical Reformatsky reaction using in situ generated organozinc intermediates under neat grinding conditions has been developed. Notable features of this reaction protocol are that it requires no solvent, no inert gases, and no pre-activation of the bulk zinc source. The developed process is demonstrated to have good substrate scope (39–82 % yield) and is effective irrespective of the initial morphology of the zinc source.
Synthesis and Applications of Unquaternized C-Bound Boron Enolates
Ng, Elvis Wang Hei,Low, Kam-Hung,Chiu, Pauline
supporting information, p. 3537 - 3541 (2018/03/21)
A general and facile method to prepare unquaternized C-bound boron enolates by a ligand-controlled O-to-C isomerization is reported. Using this protocol, C-bound pinacolboron enolates have been isolated in pure form for the first time, and have been fully characterized by NMR spectroscopy and X-ray crystallography. In contrast to the general perception, such C-boron enolates are stable without coordinative saturation at the boron. Moreover, C-boron enolates present reactivities that are distinct from the O-boron enolates, and their applications in C-O and C-C bond formations are demonstrated.
Scope and mechanism of the electrochemical Reformatsky reaction of α-haloesters on a graphite powder cathode in aqueous anolyte
De Souza, Carlos A.,Navarro, Marcelo,Bieber, Lothar W.,Areias, Madalena C.C.
, p. 118 - 126 (2014/05/06)
Six α-haloesters and eighteen carbonyl compounds were submitted to electrochemical coupling on a graphite powder cathode using aqueous anolyte free of organic solvents. Preparative yields of coupling products could be obtained with ethyl 2-bromoisobutyrate and aromatic aldehydes. Ethyl 2-bromopropionate was much less efficient. Extensive variation of applied potential, electrolyte composition, stoichiometry, catalyst, leaving halogen and activating substituents on the carbonyl compound led to the conclusion that the reaction mechanism in most cases proceeds via a radical intermediate generated from the halide reduction. Ethyl chloroacetate produced only trace amounts of coupling product, most probably by a carbanionic mechanism.
Access to enantiopure α-alkyl-β-hydroxy esters through dynamic kinetic resolutions employing purified/overexpressed alcohol dehydrogenases
Cuetos, Anibal,Rioz-Martinez, Ana,Bisogno, Fabricio R.,Grischek, Barbara,Lavandera, Ivan,De Gonzalo, Gonzalo,Kroutil, Wolfgang,Gotor, Vicente
supporting information; experimental part, p. 1743 - 1749 (2012/07/28)
α-Alkyl-β-hydroxy esters were obtained via dynamic kinetic resolution (DKR) employing purified or crude E. coli overexpressed alcohol dehydrogenases (ADHs). ADH-A from R. ruber, CPADH from C. parapsilosis and TesADH from T. ethanolicus afforded syn-(2R,3S) derivatives with very high selectivities for sterically not impeded ketones ('small-bulky' substrates), while ADHs from S. yanoikuyae (SyADH) and Ralstonia sp. (RasADH) could also accept bulkier keto esters ('bulky-bulky' substrates). SyADH also provided preferentially syn-(2R,3S) isomers and RasADH showed in some cases good selectivity towards the formation of anti-(2S,3S) derivatives. With anti-Prelog ADHs such as LBADH from L. brevis or LKADH from L. kefir, syn-(2S,3R) alcohols were obtained with high conversions and diastereomeric excess in some cases, especially with LBADH. Furthermore, due to the thermodynamically favoured reduction of these substrates, it was possible to employ just a minimal excess of 2-propanol to obtain the final products with quantitative conversions. Copyright
Cp2ZrCl2-induced Reformatsky and Barbier reactions on isatins: An efficient synthesis of 3-substituted-3-hydroxyindolin-2-ones
Chouhan, Mangilal,Sharma, Ratnesh,Nair, Vipin A.
experimental part, p. 470 - 475 (2012/02/01)
A mild and rapid one-pot process for Reformatsky and Barbier reactions using a catalytic quantity of zirconocene dichloride (Cp2ZrCl 2) as a promoter and zinc as a terminal reductant at room temperature in dimethyl formamide was developed. The protocol has wide substrate suitability and afforded the desired 3-substituted-3-hydroxyindolin-2-ones from istains in good yields and short reaction time.
Solvent-free synthesis of β-hydroxy esters and β-amino esters by indium-mediated reformatsky reaction
Chen, Xi'an,Zhang, Changfu,Wu, Huayue,Yu, Xiaochun,Su, Weike,Cheng, Jiang
, p. 3233 - 3239 (2008/09/16)
In a convenient and efficient procedure for the solvent-free synthesis of β-hydroxy esters and β-amino esters, various aldehydes and aldimines undergo a Reformatsky reaction mediated by non-activated indium at room temperature to give the corresponding esters in good to excellent yields. Georg Thieme Verlag Stuttgart.
An efficient cobalt(I)-catalysed reformatsky reaction using α-chloro esters
Lombardo, Marco,Gualandi, Alessandra,Pasi, Filippo,Trombini, Claudio
, p. 465 - 468 (2008/02/08)
An efficient cobalt(I)-catalysed Reformatsky reaction using α-chloro esters has been developed. The catalyst is prepared by reducing the cobalt(II) chloride (5%)/1,2-bis(diphenylphosphino)ethane (dppe)(5%)/zinc iodide (10%) system with zinc metal in acetonitrile in the presence of both the α-chloro ester and the carbonyl compound; good to excellent conversions to β-hydroxy esters are obtained at room temperature in 2.5 h.
Metal chloride-promoted aldol reaction of α-dimethylsilylesters with aldehydes, ketones, and α-enones
Miura, Katsukiyo,Nakagawa, Takahiro,Hosomi, Akira
, p. 1917 - 1921 (2007/10/03)
In the presence of a catalytic amount of LiCl, α-dimethylsilylesters (α-DMS-esters) 1 smoothly reacted with various aldehydes at 30°C to give aldols in good to high yields. On the other hand, the aldol reaction with ketones was effectively promoted by MgCl2 rather than by LiCl. α-Enones also underwent the metal chloride-promoted addition of 1 at the carbonyl carbon or β-carbon. Georg Thieme Verlag Stuttgart.
Catalytic generation of activated carboxylates: Direct, stereoselective synthesis β-hydroxyesters from epoxyaldehydes
Chow, Kenneth Yu-Kin,Bode, Jeffrey W.
, p. 8126 - 8127 (2007/10/03)
The catalytic generation of activated carboxylates from epoxyaldehydes enables the direct, stereoselective synthesis of β-hydroxyesters under mild, convenient reaction conditions. In addition to providing a new method for the synthesis of anti-aldol adducts, this chemistry unveils a mechanistically viable solution to the catalytic, waste-free synthesis of esters. Copyright
