10031-93-3Relevant articles and documents
Facile reaction of o-carboranyllithium reagents with functionalized alkyl halides
Cai, Jianping,Nemoto, Hiaso,Singaram, Bakthan,Yamamoto, Yoshinori
, p. 3383 - 3386 (1996)
Unlike the normal organolithium reagents, o-carboroanyllithium derivatives can tolerate many functional groups, such as ketones, nitriles and esters. This chemoselectivity is utilized in synthesizing a wide variety of o-carborane derivatives containing fu
Reductive cleavage of 1,3-dithiane systems anchored on polymers useful for supported organic syntheses
Bertini, Vincenzo,Lucchesini, Francesco,Pocci, Marco,Alfei, Silvana,De Munno, Angela
, p. 1201 - 1203 (2003)
Completely odourless reductions of ketones to alkanes through condensation with 1,3-propanedithiol copolymers and cleavage of the formed 1,3-dithiane units with sodium and ammonia or tributyltin hydride and AIBN, useful as a new synthetic methodology for combinatorial chemistry, is reported. Selective reductions of ketones in presence of an ester or a second ketone group are exemplified.
Cobalt-catalyzed cross-coupling reactions of alkyl halides with aryl Grignard reagents and their application to sequential radical cyclization/cross-coupling reactions
Ohmiya, Hirohisa,Wakabayashi, Katsuyu,Yorimitsu, Hideki,Oshima, Koichiro
, p. 2207 - 2213 (2006)
Reactions of alkyl halides with arylmagnesium bromides in the presence of cobalt(II)(diphosphine) complexes are discussed. Treatment of 1-bromooctane with phenylmagnesium bromide with the aid of a catalytic amount of CoCl 2(dppp) [DPPP=1,3-bis(diphenylphosphino)propane] yielded octylbenzene in good yield. The reaction mechanism would include single electron transfer from an electron-rich cobalt complex to alkyl halide to generate the corresponding alkyl radical. The mechanism was justified by CoCl 2(dppe)-catalyzed [DPPE=1,2-bis(diphenylphosphino)ethane] sequential radical cyclization/cross-coupling reactions of 6-halo-1-hexene derivatives that yielded benzyl-substituted cyclopentane skeletons.
Homolytic Reactions of Ligated Boranes. Part 9. Overall Addition of Alkanes to Electron-deficient Alkenes by a Radical Chain Mechanism
Baban, Jehan A.,Roberts, Brian P.
, p. 1195 - 1200 (1988)
Methyl bromoacetate and ethyl 2-bromopropanoate are reduced by Bun3P->BH3 or Bun3P->BH2Ph to methyl acetate and ethyl propanoate, respectively, in chlorobenzene at 80-110 deg C in the presence of dibenzoyl peroxide or t-butyl perbenzoate.Amine complexes of borane or phenylborane are much less effective reducing agents.The reductions may also be initiated photochemically and are inhibited by a phenolic radical scavenger.A homolytic chain mechanism is proposed in which the phosphine-boryl radical abstracts halogen from the bromo ester and is subsequently regenerated by reaction of an α-(alkoxycarbonyl)alkyl radical with the phosphine-borane.The latter propagation step, together with halogen abstraction from RI and addition of the derived alkyl radical to the C=C bond, is also involved in the chain reaction between Bun3P->BH2Ph, an alkyl iodide, and ethyl acrylate according to equation (A); Bun3P->BH3 reacts similarly but gives lower yields of ester.Reaction (A) proceeds smoothly at 110 deg C Bun3P->BH2Ph + RI + CH2=CHCO2Et -> RCH2CH2CO2Et + Bun3P->BHIPh (A) when initiated by t-butyl perbenzoate and moderate yields of isolated esters were obtained from n-butyl iodide, cyclohexyl iodide, and 3β-iodocholest-5-ene.This last iodide gives an epimeric mixture of 3α- and 3β-esters in total isolated yield of ca. 50 percent.Similar addition reactions take place between Bun3P->BH2Ph, BunI, and diethyl vinylphosphonate or phenyl vinyl sulphone.It is concluded that Bun3P->BH3 and particularly Bun3P->BH2Ph offer promise as alternatives to tin, mercury, and germanium hydrides in radical chain reactions of synthetic value.
Reductive decyanation of α-cyano and α-alkoxycarbonyl substituted nitriles promoted by samarium(II) iodide
Kang,Hong,Cho,Koh
, p. 7661 - 7664 (1995)
Decyanation of geminal dinitriles and α-alkoxycarbonyl substituted nitriles promoted by samarium(II) iodide has been efficiently achieved. This method has advantages over the previously known radical route using tin hydride with respect to applicable substrates and the reaction temperature employed. This decyanation could broaden the synthetic applicability of the nitrile derivatives.
One-step cross-coupling reaction of functionalized alkyl iodides with aryl halides by the use of an electrochemical method
Kurono, Nobuhito,Sugita, Kazuya,Takasugi, Shingo,Tokuda, Masao
, p. 6097 - 6108 (1999)
Organozinc compounds of functionalized alkyl iodide carrying an alkoxycarbonyl, cyano or alkenyl group were prepared in high yields under mild conditions (0°C-r.t., 10min in DMF) by the reaction of iodides with an electrogenerated reactive zinc (EGZn). Cross-coupling of the organozinc compounds with various aryl halides in the presence of 5 mol% Pd(P(o- Tol)3)2Cl2 in THF gave the corresponding cross-coupled products in moderate to high yields. These cross-coupling reactions can be also achieved in one step and in one pot by the use of an electrochemical method utilizing a Pt cathode and Zn anode.
Microwave-assisted aqueous Krapcho decarboxylation
Mason, Jeremy D.,Murphree, S. Shaun
, p. 1391 - 1394 (2013)
The Krapcho decarboxylation of alkyl malonate derivatives has been adapted to aqueous microwave conditions. Various salt additives were examined, and both the cation and the anion impacted the facility of the reaction. A strong correlation was found between the pKa of the anion and the reaction rate, suggesting a straightforward base-catalyzed hydrolysis. Lithium sulfate gave the best results, obviating the need for DMSO co-solvent. Georg Thieme Verlag Stuttgart · New York.
Facile preparation of organozinc bromides using electrogenerated highly reactive zinc and its use in cross-coupling reaction
Kurono, Nobuhito,Inoue, Tomio,Tokuda, Masao
, p. 11125 - 11131 (2005)
Highly reactive zinc was readily prepared by electrolysis of a DMF solution containing pyrene as a mediator with a platinum cathode and a zinc anode. Preferential reduction of pyrene occurred to generate the corresponding radical anion, which reduced zinc ions generated from anodic dissolution to give zero valent zinc with high reactivity. The reactive zinc was successfully used for an efficient transformation of bromoalkanes into the corresponding organozinc bromides. Organozinc bromides obtained were further used successfully in Pd-catalyzed cross-coupling reaction with various aryl iodides and bromides.
Unprecedented alkylation of carboxylic acids by boron trifluoride etherate
Jumbam, Ndze D.,Maganga, Yamkela,Masamba, Wayiza,Mbunye, Nomthandazo I.,Mgoqi, Esethu,Mtwa, Sphumusa
, p. 387 - 392 (2018)
The alkylation of carboxylic acids by an ethyl moiety of boron trifluoride etherate in the absence of ethyl alcohol from the reaction system is unexpected and novel. Both aromatic and aliphatic carboxylic acids were clearly alkylated affording good yields in short reaction times with the exception of nicotinic acid that necessitated an overnight reaction. It was noted that while ortho-substituted hydroxyl groups of carboxylic acids investigated were not affected by alkylation, those of meta- and para-substituted carboxylic acids were partially etherified. Furthermore, the alkylation reaction was found to be compatible with a range of functional groups such as halogens, amino and nitro groups except for the alkene function of undecylenic acid that underwent polymerisation with concomitant alkylation of its carboxylic acid function.
Cu(II)-Catalyzed Olefin Migration and Prins Cyclization: Highly Diastereoselective Synthesis of Substituted Tetrahydropyrans
Ghosh, Arun K.,Nicponski, Daniel R.
, p. 4328 - 4331 (2011)
Metal-ligand complexes of Cu(OTf)2 with an appropriate bisphosphine ligand have been shown to effectively catalyze the formation of substituted tetrahydropyrans via a sequential olefin migration and Prins-type cyclization. This methodology provides convenient access to a variety of functionalized tetrahydropyrans in excellent diastereoselectivities and good to excellent yields.
