103934-07-2Relevant academic research and scientific papers
Preparation of organoaluminum reagents from propargylic bromides and aluminum activated by PbCl2and their regio- And diastereoselective addition to carbonyl derivatives
Guo, Li-Na,Gao, Hongjun,Mayer, Peter,Knochel, Paul
supporting information; experimental part, p. 9829 - 9834 (2010/11/02)
Various propargylic and allenic aluminum reagents have been easily prepared by a direct insertion of aluminum into propargylic bromides in the presence of PbCl2 (1 mol%). These organoaluminum reagents react with carbonyl compounds to afford the
A highly atom efficient, solvent promoted addition of tetraallylic, tetraallenic, and tetrapropargylic stannanes to carbonyl compounds
McCluskey,Muderawan,Muntari,Young
, p. 7811 - 7817 (2007/10/03)
Tetraallylic, tetraallenic, and tetrapropargylic stannanes (0.25 equiv) react with aldehydes in methanol to provide unsaturated alcohols in good to excellent yields (56-99%). These reactions proceed exclusively with allylic rearrangement for tetra(2-butenyl)tin 2b and tetra(1,2-butadienyl)-tin 16c and predominantly with allylic rearrangement for tetrapropadienyltin 16a and tetra(2-butynyl)tin 6e. Allylation reactions also proceeded smoothly with reactive ketones such as ethyl pyruvate (9a) and cyclohexanone (9b). The corresponding TFA-catalyzed reactions of dimethyl acetals 4d and 4e are regiospecific with allylic rearrangement.
An Effective and Selective Conjugate Propargylation Reaction of Stannylallenes to α,β-Unsaturated Carbonyl Compounds and α-Nitro Olefins
Haruta, Jun-ichi,Nishi, Koichi,Matsuda, Satoshi,Akai, Shuji,Tamura, Yasumitsu,Kita, Yasuyuki
, p. 4853 - 4859 (2007/10/02)
Stannylallenes (1) reacted with α,β-unsaturated carbonyl compounds and α-nitro olefins in the presence of TiCl4 to give the corresponding conjugate propargylation products.Thus, the reaction of 1 with cyclic and acyclic α,β-unsaturated carbonyl compounds (2) gave β-propargylic ketones (3) in high yields.With α-nitro olefins (4), two types of products, β-propargylic nitroalkanes (5) and α-propargylic ketones (6), were obtained selectively depending on the presence or absence of the α-substituent of 4.Transformation of the products (6) to cyclopentenone derivatives (10 and 12) are also described.
Scope and Stereochemical Course of the Addition of (Trimethylsilyl)allenes to Ketones and Aldehydes. A Regiocontrolled Synthesis of Homopropargylic Alcohols
Danheiser, Rick L.,Carini, David J.,Kwasigroch, Carrie A.
, p. 3870 - 3878 (2007/10/02)
The reaction of (trimethylsilyl)allenes with aldehydes and ketones in the presence of titanium tetrachloride provides a regiocontrolled route to homopropargylic alcohols of a variety of substitution types.The addition of 1-alkyl-substituted (trimethylsilyl)allenes to carbonyl compounds furnishes the desired acetylenes directly, while reactions involving allenylsilanes 6,7, and 9 initially produce mixtures of acetylenes and (trimethylsilyl)vinyl chloride derivatives.Exposure of these mixtures to the action of potassium fluoride in dimethyl sulfoxide then generates the desired homopropargylic alcohols.The addition of the chiral allenylsilane 9 to achiral aldehydes has been found to proceed with modest (3-4:1) diastereoselectivity to produce mainly syn (erythro) homopropargylic alcohols.
