1462-97-1Relevant academic research and scientific papers
Deoxygenative Borylation of Secondary and Tertiary Alcohols
Friese, Florian W.,Studer, Armido
supporting information, p. 9561 - 9564 (2019/06/21)
Two different approaches for the deoxygenative radical borylation of secondary and tertiary alcohols are presented. These transformations either proceed through a metal-free silyl-radical-mediated pathway or utilize visible-light photoredox catalysis. Readily available xanthates or methyl oxalates are used as radical precursors. The reactions show broad substrate scope and high functional-group tolerance, and are conducted under mild and practical conditions.
Efficient chemoselective addition of grignard reagents to carbonyl compounds in 2-methyltetrahydrofuran
Zhong, Weihui,Wu, Yaotiao,Zhang, Xingxian
experimental part, p. 370 - 373 (2009/12/25)
Compared with tetrahydrofuran (THF) as a solvent for the addition reactions between Grignard reagents and carbonyl compounds 2-methyltetrahydrofuran affords the corresponding adducts in higher yields with higher chemoselectivities. Moreover, 2-methyltetrahydrofuran can be readily recycled and reused, which lowers the cost of the process and makes the reaction greener.
Solutions of anhydrous lanthanide salts and its preparation
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, (2008/06/13)
The present invention relates to anhydrous solutions of MX 3 €¢z LiA in a solvent, wherein M is a lanthanide including lanthanum, or yttrium or indium; z > 0; and X and A are independently or both monovalent anions, preferably Cl, Br or I. The solution is readily prepared by dissolving or suspending MX 3 or its hydrate and z equiv LiA in water or hydrophilic solvents, or mixtures thereof, removing the solvent under vacuum and dissolving the resulting powder in another solvent. The solution of MX 3 €¢z LiA can advantageously be used e.g. in addition reactions of Grignard reagents to ketones and imines. Even the catalytic use of MX 3 €¢z LiA is possible. Also claimed are a method for preparing the anhydrous solutions, the use of such solution in a chemical reaction and chemical compositions MX 3 €¢z LiA, with M, z, X and A as indicated above.
Soluble lanthanide salts (LnCl3,·2 LiCl) for the improved addition of organomagnesium reagents to carbonyl compounds
Krasovskiy, Arkady,Kopp, Felix,Knochel, Paul
, p. 497 - 500 (2007/10/03)
(Chemical Equation Presented) Easy-to-prepare solutions of LnCl 3·2 LiCl (Ln = La, Ce, Nd) (0.3-0.5 M in THF) are a unique source of soluble lanthanide salts with versatile applications in organic synthesis. These salts can serve as promoters or catalysts for the addition of organometallic compounds to sterically hindered, enolizable or α,β-unsaturated ketones or imines.
Stereoselective nickel and manganese catalyzed cyclizations of 5-haloketones
Stiidemann, Thomas,Ibrahim-Ouali, Malika,Cahiez, Gérard,Knochel, Paul
, p. 143 - 144 (2007/10/03)
The treatment of various 5-iodoketones or 5-bromoketones with Et2Zn in the presence of either Ni(acac)2 (5 mol %) or MnBr2/ CuCl (5 mol %) produces functionalized substituted cyclopentanols bearing in some cases contiguous
Alkylation-annulation of halo esters with organometallic reagent/SmI2 couple leading to cycloalkanols: A facile cyclopropanol synthesis from a 3-halo ester
Fukuzawa, Shin-Ichi,Furuya, Hideki,Tsuchimoto, Teruhisa
, p. 1953 - 1960 (2007/10/03)
Transformation of a 3-halo ester to cyclopropanols has been accomplished in excellent yields under mild conditions employing a coupled reagent of samarium(II) diiodide with organometallic reagents. 5- and 6-Halo esters were also transformed into cyclopentanols and cyclohexanols, respectively, in low to moderate yields. The reaction with a 4-halo ester gave 2,2-disubstituted tetrahydrofuran as a major product that resulted from double alkylation followed by cyclization; a substituted cyclobutanol was formed in poor yield.
Synthesis of α-Hydroxy Ketones by Direct, Low-Temperature, in Situ Nucleophilic Acylation of Aldehydes and Ketones by Acyllithium Reagents
Seyferth, Dietmar,Weinstein, Robert M.,Hui, Richard C.,Wang, Wei-Liang,Archer, Colin M.
, p. 5620 - 5629 (2007/10/02)
The reaction of n-, sec-, and tert-butyllithium with CO at atmospheric pressure at -110 and -135 deg C in the appropriate solvent system in the presence of ketones and aldehydes generates the acyllithium, RC(O)Li, which reacts with the carbonyl compound to give the α-hydroxy ketone, generally in good yield.Reactions with aldehydes are limited in scope, working well with the t-BuLi-derived acyllithium reagents, but not with n-BuC(O)Li.
METAL-HALOGEN EXCHANGE-INITIATED CYCLIZATION OF IODO CARBONYL COMPOUNDS
Cooke, Manning P.,Houpis, Ioannis N.
, p. 4987 - 4990 (2007/10/02)
The feasability of constructing carbocycles through the metal-halogen exchange-initiated cyclization reactions of iodoketones and other carboxyl derivatives has been studied.With saturated primary iodides, cyclization predominates when deactivated ketones are employed.
Carbon-Carbon Bond-Forming Reactions Using Cerium Metal or Organocerium(III) Reagents
Imamoto, Tsuneo,Kusumoto, Tetsuo,Tawarayama, Yoshinori,Sugiura, Yasushi,Mita, Takeshi,et al.
, p. 3904 - 3912 (2007/10/02)
Carbon-carbon bond-forming reactions using cerium metal or organocerium(III) reagents have been investigated.Cerium amalgam is an effective reagent for the chemoselective preparation of homoallylic alcohols from allyl halides and carbonyl compounds.These same reagent can also be satisfactorily employed for the Reformatsky-type reaction of α-halo esters with carbonyl compounds.It has been shown that organocerium(III) reagents are conveniently generated by the reaction of organolithiums with cerium(III)iodide or cerium(III)chloride.The reagents are less basic thanorganolithiums or Grignard reagents, and they react cleanly at -78 to -65 deg C with various carbonyl compounds to afford the addition products in high yields, even though the substrates are susceptible to enolization or metal-halogen exchange with simple organolithiums.The same reagents react also with α,β-unsaturated compounds to yield 1,2-addition products in high selectivity.
