53723-35-6Relevant academic research and scientific papers
Nonracemic homopropargylic alcohols via asymmetric allenylboration with the robust and versatile 10-TMS-9-borabicyclo[3.3.2]decanes
Lai, Chunqiu,Soderquist, John A.
, p. 799 - 802 (2007/10/03)
(Chemical Equation Presented) The asymmetric allenylboration of representative aldehydes with the stable, storable 1 is reported. Easily and efficiently prepared in either enantiomeric form from the air-stable crystalline 4 through simple Grignard procedures, 1 gives 6 cleanly. The latter is easily isolated in high yield and ee with predictable stereochemistry. The procedure also regenerates 4 for its direct conversion back to 1 and facilitates the efficient recovery of the pseudoephedrine. The net process is the synthetic equivalent of the asymmetric addition of allenylmagnesium bromide to aldehydes.
Selective Propargylation of Carbonyl Compounds with Allenylstannane/Alkyllithium Mixed Reagents
Suzuki, Masaaki,Morita, Yasushi,Noyori, Ryoji
, p. 441 - 449 (2007/10/02)
1-Substituted allenyltrialkylstannanes readily undergo transmetalation with an alkyllithium to generate a tetraalkylstannane and an equilibrating mixture of the allenyl- and propargyllithium compounds.The organolithium derivatives react with a variety of aldehydes and ketones at low temperature to give, after aqueous workup, the regioisomeric acetylenic and allenic carbinols in high yields.The degree of the regioselection is highly sensitive to the steric and electronic properties of the carbonyl substrates.Excellent acetylene selectivities are obtainable by combination of the bulky reagents and substrates or by using acylsilanes as carbonyl components.The origin of the regioselectivity is discussed.
