68060-18-4Relevant academic research and scientific papers
Congested C-C bonds by Pd-catalyzed enantioselective allyl-allyl cross-coupling, a mechanism-guided solution
Ardolino, Michael J.,Morken, James P.
, p. 7092 - 7100 (2014/06/09)
Under the influence of a chiral bidentate diphosphine ligand, the Pd-catalyzed asymmetric cross-coupling of allylboron reagents and allylic electrophiles establishes 1,5-dienes with adjacent stereocenters in high regio-and stereoselectivity. A mechanistic study of the coupling utilizing reaction calorimetry and density functional theory analysis suggests that the reaction operates through an inner-sphere 3,3′-reductive elimination pathway, which is both rate-defining and stereodefining. Coupled with optimized reaction conditions, this mechanistic detail is used to expand the scope of allyl-allyl couplings to allow the generation of 1,5-dienes with tertiary centers adjacent to quaternary centers as well as a unique set of cyclic structures.
Construction of 1,5-enynes by stereospecific Pd-catalyzed allyl-propargyl cross-couplings
Ardolino, Michael J.,Morken, James P.
supporting information; experimental part, p. 8770 - 8773 (2012/07/02)
The palladium-catalyzed cross-coupling of chiral propargyl acetates and allyl boronates delivers chiral 1,5-enynes with excellent levels of chirality transfer and can be applied across a broad range of substrates.
Diastereocontrol in asymmetric allyl-allyl cross-coupling: Stereocontrolled reaction of prochiral allylboronates with prochiral allyl chlorides
Brozek, Laura A.,Ardolino, Michael J.,Morken, James P.
supporting information; experimental part, p. 16778 - 16781 (2011/12/04)
Palladium-catalyzed allyl-allyl cross-coupling was investigated with substituted prochiral allylic boronates. These reactions deliver products bearing adjacent stereocenters, and the issue of diastereocontrol is therefore paramount. Under appropriately mo
Oxovanadium-induced oxidative desilylation of allylic and benzylic silanes
Fujii, Takashi,Hirao, Toshikazu,Ohshiro, Yoshiki
, p. 5601 - 5604 (2007/10/02)
Cinnamyltrimethylsilane underwent desilylation via one-electron oxidation with VO(OEt)Cl2, which was applied to the cross-coupling with the less oxidizable allylic silanes to give the corresponding 1,5-hexadienes. Chlorination or aromatization
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).
