mixtures of isomers and substantial polymerization. The reaction took place under exceptionally mild reaction conditions and very low catalyst loading (0.5 mol %). DFT calculations disclose the mechanistic features of the isomerization and account for the high selectivity displayed by the B(C6 F5 )3 catalyst. The synthetic applicability of the newreaction is demonstrated by the preparation of γ-chiral
The rhodium-catalyzed controllable diverse arylation of 2,5-dihydrofuran with arylboronic acids is reported. By fine-tuning of the reaction conditions, four different ring-opening or oxidative arylation pathways are controlled in the rhodium-catalyzedarylation of 2,5-dihydrofuran, granting selective access to 2-aryl or 3-aryl homoallylic alcohols and 3-aryl or 4-aryl-2,3-dihydrofurans. The catalytic
Scandium(III) triflate catalyzed synthesis of primary homoallylic alcohols via carbonyl-ene reaction
作者:Sabera Sultana、Somasekhar Bondalapati、Kiran Indukuri、Paramartha Gogoi、Pipas Saha、Anil K. Saikia
DOI:10.1016/j.tetlet.2013.01.046
日期:2013.3
Scandium trifluoromethanesulfonate can efficiently catalyze the formation of homoallylic alcohols from olefins and paraformaldehyde in good yields. (c) 2013 Elsevier Ltd. All rights reserved.
Enantioselective Small Molecule Synthesis by Carbon Dioxide Fixation using a Dual Brønsted Acid/Base Organocatalyst
作者:Brandon A. Vara、Thomas J. Struble、Weiwei Wang、Mark C. Dobish、Jeffrey N. Johnston
DOI:10.1021/jacs.5b04425
日期:2015.6.17
Carbon, dioxide exhibits many of the qualities of an ideal reagent: it is nontoxic, plentiful, and inexpensive. Unlike other gaseous reagents, however, it has found limited use in enantioselective synthesis. Moreover, unprecedented is a tool that merges one of the Simplest biological :approaches to catalysis-Bronsted acid/base activation with this abundant reagent. We describe a metal-free small molecule catalyst that achieves the three component reaction between a homoallylic alcohol, carbon dioxide, and an electrophilic Source of iodine. Cyclic carbonates are formed enantioselectively.