Catalytic 1,3-Difunctionalisation of Organic Backbones through a Highly Stereoselective, One-Pot, Boron Conjugate-Addition/Reduction/Oxidation Process
作者:Cristina Solé、Amolak Tatla、Jose A. Mata、Andrew Whiting、Henrik Gulyás、Elena Fernández
DOI:10.1002/chem.201102081
日期:2011.12.9
enantioselectivity provided by the CuI catalyst modified with Josiphos‐ and Mandyphos‐type ligands has been examined. The oxidative substitution of the boryl unit with a hydroxyl group proceeds with complete retention of configuration at the Cβ‐atom. In parallel, the stoichiometric reduction of the imino or carbonyl group provides a second stereogenic centre. Depending on the nature of the reducing reagent
Highly Enantio- and Diastereoselective Synthesis of γ-Amino Alcohols from α,β-Unsaturated Imines through a One-Pot β-Boration/Reduction/Oxidation Sequence
enantioselectivities (up to 99% ee). For the stoichiometric reduction of the imino group, it has been found that high levels of 1,3-diastereocontrol can be achieved using achiral reducing agents. A new methodology for the synthesis of both diastereoisomers, syn and anti, has been established. The last step of the reaction sequence, oxidative substitution of the boryl unit with a hydroxy group, proceeds with
Reduction of 2,3-Dihydroisoxazoles to β-Amino Ketones and β-Amino Alcohols
作者:Patrick Aschwanden、Lisbet Kværnø、Roger W. Geisser、Florian Kleinbeck、Erick M. Carreira
DOI:10.1021/ol052540c
日期:2005.12.1
[chemical reaction: see text]. We report the reduction of 2,3-dihydroisoxazoles to beta-amino ketones and beta-amino alcohols. The latter are obtained in high diastereoselectivity with preference for the syn isomer.