37050-03-6

Upstream product

• 13721-54-5 Vinylethylacetylen 
• 2417-93-8 propyllithium 
• 693-03-8 n-butyl magnesium bromide 
• 109182-79-8 1-bromo-penta-1,2-diene 
• 925-90-6 ethylmagnesium bromide 
• 129835-56-9 (2R,3R)-3-((R)-1-Ethynyl-pentyloxy)-butan-2-ol 
• 110-62-3 pentanal 
• 129835-53-6 4(R),5(R)-dimethyl-2-butyl-1,3-dioxolane 

Relevant academic research and scientific papers

Reaction of 1-bromo-1,2-dienes with alkylcuprates as a regio- and stereo-selective route to acetylenic or allenic compounds

Alkylcuprates react with 1-bromo-1,2-dienes to give allenic and/or acetylenic products.The selectivity of the crosscoupling is markedly dependent on the nature of the copper reagent, which plays a prominent role in determining both the regio- and the stereo-chemistry.The preparative aspects of these copper-induced reactions are discussed and their possible mechanism discussed.

Mechanistic aspects on the formation of chiral allenes from propargylic ethers and organocopper reagents

Propargylic ethers react with organocopper reagents to afford allenes by a syn addition to the triple bond followed by a β-elimination of the resulting alkenyl copper species. With use of chiral propargylic ethers and stoichiometric organocopper reagent, it was shown that the β-elimination step is purely anti, resulting in the formation of a chiral allene with 96% optical yield. The same reaction, run with a Grignard reagent RMgX and a catalytic amount of a Cu1 salt, affords allenes through an anti or syn overall process. The crucial step is the β-elimination of the intermediate alkenyl organometallic species, which is of anti type with RMgI and of syn type with RMgCl. Propargylic acetates, which also afford allenes in this reaction, but through a CuIII intermediate, are not sensitive to this "halogen effect".

REACTIONS OF 3-ALKYL- AND 3,3-DIALKYL-1-BROMOALLENES WITH ORGANOCUPRATES: EFFECTS OF THE NATURE OF THE CUPRATE REAGENT ON THE REGIO- AND STEREOSELECTIVITY

Organocuprates induce 1,3- and direct substitution in 3-alkyl- and 3,3-dialkyl-1-bromo-1,2-dienes leading respectively to either terminal acetylenes or allenic hydrocarbons.The nature of the cuprate exerts a prominent role in determining both the regio- and the stereochemistry of these reactions.