29887-38-5Relevant articles and documents
Nickel-catalyzed double bond transposition of alkenyl boronates for in situ syn-selective allylboration reactions
Weber, Felicia,Ballmann, Monika,Kohlmeyer, Corinna,Hilt, Gerhard
supporting information, p. 548 - 551 (2016/02/18)
The transposition of a homoallyl pinacol boronic ester was realized by a highly reactive nickel-catalyst system comprising NiCl2(dppp), zinc powder, ZnI2, and Ph2PH. The in situ generated Z-crotyl pinacol boronic esters were reacted with various aldehydes to form syn-homoallylic alcohols in high diastereoselectivities. The present nickel-catalyzed reaction is complementary to the iridium-catalyzed transposition reported by Murakami leading to the corresponding anti-homoallylic alcohols. Also, the multiple transposition of pentenyl pinacol boronic ester was realized.
Allylic Sulfones as Allyl Anion Equivalents: Homoallylic Alcohols from Metal Catalysed Reactions of Sulfones with Aldehydes and Ketones
Clayden, Jonathan,Julia, Marc
, p. 1905 - 1906 (2007/10/02)
Reduction of allylic sulfones with diethylzinc, catalysed by palladium(0), gives nucleophilic organometallic species, which react in situ with carbonyl compounds to give homoallylic alcohols in high yield.
Barbier-type allylation of carbonyl compounds and imines with metallic cadmium
Sain, Bir,Prajapati, Dipak,Sandhu, Jagir S.
, p. 4795 - 4798 (2007/10/02)
Cadmium mediated allylation of a variety of carbonyl compounds and imines in a Cd/Bu4NBr/THF system afforded excellent yields of the corresponding homoallylic alcohols and amines under very mild reaction conditions.
Oxalic acid catalyzed isoprenic coupling: a simple experimental procedure.
Bertrand, M.,Waegell, B.,Zahra, J. P.
, p. 904 - 910 (2007/10/02)
Oxalic acid, which is considered as a mild acid, allows a smooth dehydration- without polymerisation- of 2-methylbut-3-en-2-ol 1 into isoprene with around 46percent yield.The remander of the reaction mixture featuring a nice fragance, consists of a mixture of 25 identified products composed of a set of cyclic and non cyclic ethers, and of monoterpenes.Fourteen products could be isolated by preparative vapor phase chromattography and identified with authentic products by 1H and 13C NMR.The formation of the observed products can be rationalized on the basis of currently admitted reaction mechanisms. Key words: isoprene / isoprene coupling / monoterpenic alcohols
Synthesis of Homoallylic Alcohols in Aqueous Media
Wilson, Stephen R.,Guazzaroni, Maria E.
, p. 3087 - 3091 (2007/10/02)
The reaction of aldehydes or ketones with allyl halides/Zn takes place readily in aqueous NH4Cl solution in the presence of C-18 silica as a solid organic cosolvent.This efficient and high-yield reaction parallels the Grignard reaction in terms of stereo- and regioselectivity.There are two applications, however, where this process has special advantages.The formation of the Grignard reagent with dimethylallyl halides is plagued by coupling side products while our aqueous cases react smoothly.Another advantage is that the reaction can be carried out without the protection of additional hydroxy functional groups.A diverse selection of examples are presented, and a potential mechanism is discussed.
UN EQUIVALENT SYNTHETIQUE CHIRAL DU PRENAL, LE FORMYL-TRIMETHYLENEMETHANE(FER)TRICARBONYLE. SYNTHESE DU (R)-(-)-IPSDIENOL
Franck-Neumann, Michel,Martina, Daniel,Heitz, Marie-Paule
, p. 6679 - 6682 (2007/10/02)
Formyl-TMM (Iron)tricarbonyl 3 reacts with a high diastereoselectivity with organozinc derivatives to Iron stabilized TMM-alcohols.These are decomplexed, under partial hydrogenation, by photolysis in acetic acid to give allylic and homoallylic isoprenoic alcohols.Starting from the optically active complex (+)-3, this allows a rapid synthesis of (R)-(-)-Ipsdienol of high ee.
SYNTHESIS AND REACTIONS OF SULFONES - AN EQUIVALENT FOR THE -WITTIG REARRANGEMENT OF NONCONJUGATED SECONDARY CARBANIONS
Brueckner, Reinhard,Peiseler, Beate
, p. 5233 - 5236 (2007/10/02)
The title compounds 4 are prepared from allylic alcohols 1 and tosyldiazomethane.Their anions undergo -Wittig rearrangements which allow the incorporation of additional carbon atoms into the molecule.
Indium in Organic Synthesis: Indium-Mediated Allylation of Carbonyl Compounds
Araki, Shuki,Ito, Hirokazu,Butsugan, Yasuo
, p. 1831 - 1833 (2007/10/02)
Indium-mediated allylation of a variety of ketones and aldehydes afforded excellent yields of the corresponding homoallylic alcohols under very mild reaction conditions.
HIGHLY REACTIVE METALS FROM POTASSIUM-GRAPHITE. PREPARATION AND USE OF TITANIUM-GRAPHITE AND TIN-GRAPHITE
Boldrini, Gian Paolo,Savoia, Diego,Tagliavini, Emilio,Trombini, Claudio,Umani-Ronchi, Achille
, p. 307 - 312 (2007/10/02)
The potassium-graphite route to active forms of metals has been extended to the preparation of titanium-graphite (Ti-Gr) and tin-graphite (Sn-Gr).The Ti-Gr is used to achieve the reductive coupling of ketones to give alkenes, and Sn-Gr is used in the preparation of diallyltin dibromide complexes which react with aldehydes to give homoallylic alcohols.
Highly Selective Carbon-Carbon Bond Forming Reactions Mediated by Chromium(II) Reagents
Hiyama, Tamejiro,Okude, Yoshitaka,Kimura, Keizo,Nozaki, Hitosi
, p. 561 - 568 (2007/10/02)
A low valent chromium reagent is generated from chromium(III) chloride and a half mol of lithium aluminum hydride in tetrahydrofuran.The reagent behaves similarly to anhydrous chromium(II) chloride, which is commercially available, and reduces allylic halides to produce unisolable allylchromium species which add efficiently to aldehydes or ketones with high degree of stereo- and chemoselectivity.Particularly, high threo selectivity is observed in the reaction of aldehydes and 1-bromo-2-butene and is ascribed to a chair-like six-membered transition state.Simple reduction od allylic and benzylic halides produces biallyls and bibenzyls, while gem-dibromocyclopropanes afford the corresponding allenes in excellent yields.
