68060-19-5Relevant academic research and scientific papers
Selective Alkylation and Allylation of Allylic Halides by Tetraorganoidates: Regio- and Stereo-selective Synthesis of Rosefuran and Sesquirosefuran
Araki, Shuki,Jin, Shun-Ji,Butsugan, Yasuo
, p. 549 - 552 (2007/10/02)
Tetraalkylindanes regioselectively alkylate allylic bromides at the α-carbon.In this way, 1,5-dienes have been regio- and stereo-selectively synthesized by the allyl-allyl coupling of allylic bromides and allylic indates, including rosefuran 1 and sequirosefuran 3.
Reaction Of Allylic Boron and Aluminium "Ate" Complexes with Organic Halides and Carbonyl Compounds. Trialkylboranes as Regio-, Stereo-, and Chemoselective Control Elements
Yamamoto, Yoshinori,Yatagai, Hidetaka,Maruyama, Kazuhiro
, p. 1969 - 1975 (2007/10/02)
Lithium allylic boron ate complexes, prepared by the addition of trilakylboranes to an ether solution of allylic lithium compounds, regioselectively react with allylic halides to produce head-to-tail 1,5-dienes (eq 1).The ate complexes are also prepared from the reaction of allylic boranes with alkyllithium derivatives.Magnesium or copper allylic boron ate complexes are less effective.Lithium crotyl boron ate complexes undergo a rapid reaction with aldehydes with good threoselectivity (eq 2).The selectivity is affected by the steric hindrance of trialkylboranes, as explained by the steric parameters of the 6-membered transition state.The ate complexes react with α,β-unsaturated ketones in a competitive manner of 1,2 and 1,4 addition, while they add to cinnamaldehyde exclusively in a 1,2 manner.The chemoselective aspects are only investigated. 1H and 13 C NMR spectra of lithium allylic boron ate complexes clearly indicate (i) the prevention of allylic rearrangement, (ii) the predominant trans geometry of the crotyl unit in comparison with the corresponding trivalent crotylboron, and (iii) the relative importance of ?-? conjugation between the double bond and the carbon-boron bond (eq 3).
