79015-63-7Relevant academic research and scientific papers
Zinc catalyzed and mediated propargylations with propargyl boronates
Fandrick, Daniel R.,Fandrick, Keith R.,Reeves, Jonathan T.,Tan, Zhulin,Johnson, Courtney S.,Lee, Heewon,Song, Jinhua J.,Yee, Nathan K.,Senanayake, Chris H.
supporting information; experimental part, p. 88 - 91 (2010/03/03)
Chemical Equation Presented The utility of allenyl and propargyl boronates for the propargylation of aldehydes and ketones mediated by zinc is presented. The reaction is catalytic in zinc with allenyl or propargyl borolanes. The propargylation with crystalline and air-stable propargyl diethanolamine boronates was also achieved. A catalytic cycle is proposed, and preliminary mechanistic studies are discussed.
Preparation of oxetanes by silicon-directed 4-exo trig electrophilic cyclisations of homoallylic alcohols
Rofoo, Mazin,Roux, Marie-Claude,Rousseau, Gérard
, p. 2481 - 2484 (2007/10/03)
The reaction of homoallylic alcohols with bis(sym-collidine)bromine(I) hexafluoroantimonate led in good yields to the formation of oxetanes if a silyl group was fixed on the carbon-carbon double bond in terminal position. This reaction was stereospecific when no supplementary substituent was present on the double bond.
Palladium(II)-catalyzed formation of γ-butyrolactones from 4-trimethylsilyl-3-alkyn-1-ols: Synthetic and mechanistic aspects
Compain, Philippe,Gore, Jacques,Vatele, Jean-Michel
, p. 10405 - 10416 (2007/10/03)
γ-butyrolactones are obtained in good yields from 4-trimethylsilyl-3-alkyn-1-ols via Wacker-type oxidation reaction. A mechanism is proposed for this transformation: it involves two successive trans-hydroxypalladations followed by a [PdXSiMe3] syn-elimination and explains why the presence of the silyl group is essential in such a process.
Gallium-Mediated Highly Regioselective Reactions of Trimethylallylpropargyl Bromide and Trimethylsilylallyl Bromide with Carbonyl Compounds
Han, Ying,Huang, Yao-Zeng
, p. 9433 - 9434 (2007/10/02)
One-pot reactions of gallium powder, trimethylsilylpropargyl bromide, aldehydes or ketones in the presence of KI and LiCl show very high acetylenic selectivity and under the same conditions, trimethylsilylallyl bromide also exhibits very high selectivity
Selective Mono- and Polymethylene Homologations of Copper Reagents Using (Iodomethyl)zinc Iodide
Sidduri, AchyuthaRao,Rozema, Michael J.,Knochel, Paul
, p. 2694 - 2713 (2007/10/02)
A wide range of unsaturated aryl-, alkenyl-, alkynylcopper compounds can be selectively homologated by a methylene unit using (iodomethyl)zinc iodide or bis(iodomethyl)zinc.These reactions allow the generation of mixed allylic zinc-copper compounds which can be efficiently trapped with carbonyl compounds.An application to a general preparation of functionalized α-methylene-γ-butyrolactones is described.The homologation of alkynylcoppers with (iodomethyl)zinc iodide allows a one-pot preparation of propargylic copper reagents which in the presence of a carbonyl compound provide various homopropargylic alcohols in excellent yields.In the absence of an electrophile, a clean quadruple methylene homologation of alkynylcoppers occurs to furnish dienic copper reagents.The homologation of other types of copper reagents is also possible, and carbanions at the α-position to amines as well as homoenolates of aldehydes or ketones can also be prepared by this method.
Reactions of Carbonyl Compounds with diisobutyltelluronium Bromide Mediated by Different Strong Bases: Highly Regioselective Synthesis of (Trimethylsilyl)propargyl Alcohol and Highly Stereoselective Synthesis of cis-(Trimethylsilyl)alkynyl Epoxides
Zhou, Zhang-Lin,Huang, Yao-Zeng,Shi, Li-Lan,Hu, Jiong
, p. 6598 - 6603 (2007/10/02)
diisobutyltelluronium bromide (1), after being treated with alkyl- or aryllithium reagent, undergoes a lithium-tellurium exchange reaction via an unstable transient tetraorganyltellurium intermediate, and the in situ generated lithium species react with carbonyl compounds to give (trimethylsilyl)propargyl alcohols 2 in high yields with high regioselectivity.However, when the telluronium salt 1 was treated with nonnucleophilic bases such as LDA or lithium 2,2,6,6-tetramethylpiperidide, the moderately stabilized silylated telluronium ylide formed.The silylated telluronium ylide reacted with carbonyl compounds to afford (trimethylsilyl)alkynyl epoxides 11 in good to excellent yields with high cis stereoselectivity.
SILANES IN ORGANIC SYNTHESIS. 11. REGIOCONTROLLED SYNTHESIS OF α-HYDROXYMETHYLATED (TRIMETHYLSILYL)ALLENES
Daniels, Rhys G.,Paquette, Leo A.
, p. 1579 - 1582 (2007/10/02)
The organometallic produced by reaction of trimethylsilylpropargyl bromide with aluminium amalgam in anhydrous tetrahydrofuran condenses readily with aldehydes and ketones to give allenic alcohols resulting from coupling α to the trimethylsilyl substituen
