151918-10-4Relevant articles and documents
Asymmetric Petasis Borono-Mannich Allylation Reactions Catalyzed by Chiral Biphenols
Jiang, Yao,Schaus, Scott E.
supporting information, p. 1544 - 1548 (2017/02/05)
Chiral biphenols catalyze the asymmetric Petasis borono-Mannich allylation of aldehydes and amines through the use of a bench-stable allyldioxaborolane. The reaction proceeds via a two-step, one-pot process and requires 2–8 mole % of 3,3′-Ph2-BINOL as the optimal catalyst. Under microwave heating the reaction affords chiral homoallylic amines in excellent yields (up to 99 %) and high enantioselectivies (er up to 99:1). The catalytic reaction is a true multicomponent condensation reaction whereas both the aldehyde and the amine can possess a wide range of structural and electronic properties. Use of crotyldioxaborolane in the reaction results in stereodivergent products with anti- and syn-diastereomers both in good diastereoselectivities and enantioselectivities from the corresponding E- and Z-borolane stereoisomers.
An efficient three-component synthesis of homoallylic amines catalysed by MgI2 etherate
Wang, Yanping,Liu, Yingshuai,Hu, Shenghui,Zhang, Xingxian
experimental part, p. 21 - 24 (2012/03/27)
A three-component reaction of aldehydes, amines and allyltributylstannane was efficiently carried out to afford the corresponding homoallylic amine derivatives in the presence of 20 mol% of MgI2 etherate [(MgI 2?(OEt2)n] under mild and neutral reaction conditions in good to excellent yields.
Studies on the bisoxazoline- and (-)-sparteine-mediated enantioselective addition of organolithium reagents to imines
Denmark, Scott E.,Nakajima, Noriyuki,Stiff, Cory M.,Nicaise, Olivier J.-C.,Kranz, Michael
experimental part, p. 1023 - 1045 (2009/05/30)
The enantioselective addition of organolithium reagents to N-anisylaldimines promoted by chiral bisoxazolines and (-)-sparteine as external ligands is described. This reaction proceeds readily with a wide range of aldimine substrates (aliphatic, aromatic, olefinic) and organolithium nucleophiles (Me, n-Bu, Ph, vinyl) in excellent yields (81-99%) and with high enantioselectivities (up to 97:3.0 er). The external ligands can be used in substoichiometric amounts albeit with slightly attenuated enantioselectivities. A systematic evaluation of the structural features of the bisoxazolines revealed a primary contribution from the substituent at C(4) and a secondary influence from the bridging substituents. A computational analysis (PM3) provided a clear rationalization for the origin of enantioselectivity.