Indium-Mediated, Highly Efficient and Diastereoselective Addition of Cyclic Secondary Allylic Bromides to Carbonyl Compounds
作者:Faiz Ahmed Khan、B. Prabhudas
DOI:10.1016/s0040-4020(00)00672-4
日期:2000.9
Indium-mediated addition of 3-bromocyclohexene and 3-bromocyclooctene to a variety of aromatic aldehydes and cyclohexanone proceeds smoothly with excellent syn diastereoselectivity to produce the corresponding cycloalkenyl substituted homoallylic alcohols in good to high yields.
Bi(cyclopentyl)diol-Derived Boronates in Highly Enantioselective Chiral Phosphoric Acid-Catalyzed Allylation, Propargylation, and Crotylation of Aldehydes
作者:Jinping Yuan、Pankaj Jain、Jon C. Antilla
DOI:10.1021/acs.joc.0c01646
日期:2020.10.16
catalytic addition of bi(cyclopentyl)diol-derived boronates to aldehydes promoted by chiralphosphoricacids, allowing for the formation of enantioenriched homoallylic, propargylic, and crotylic alcohols (up to >99% enantiomeric excess (ee), diastereomeric ratio (dr) >20:1). These boronate substrates provided superior enantioselectivities, allowing for the reactions to proceed with low catalyst loading
Iridium-Catalyzed C−C Coupling via Transfer Hydrogenation: Carbonyl Addition from the Alcohol or Aldehyde Oxidation Level Employing 1,3-Cyclohexadiene
作者:John F. Bower、Ryan L. Patman、Michael J. Krische
DOI:10.1021/ol800159w
日期:2008.3.1
Under hydrogen autotransfer conditions employing a catalyst derived from [Ir(cod)Cl]2 and BIPHEP, 1,3-cyclohexadiene (CHD) couples to benzylic alcohols 1a-9a to furnish carbonyl addition products 1c-9c, which appear as single diastereomers with variable quantities of regioisomeric adducts 1d-9d. Under related transferhydrogenation conditions employing isopropanol as terminal reductant, identical carbonyl
Preparation and stereoselective additions of highly substituted cyclic allylzinc reagents a zinc-ene cyclization
作者:Nicolas Millot、Paul Knochel
DOI:10.1016/s0040-4039(99)01689-5
日期:1999.10
Highly substituted cyclic allylzinc reagents 2 have been prepared by fragmentation of stericallyhindered homoallylic zinc alcoholates 1. Their reactions with aldehydes proceed under mild conditions and are highly stereoselective (64–86 %; Examples of acylation with benzonitrile and zinc-ene cyclization giving new spirobicyclic zinc reagents are also reported.
Ï-Allylpalladium complexes could be generated in water by the palladium(0) water soluble catalyst prepared in situ from palladium acetate and TPPTS. These complexes were transmetalated with indium to react with benzaldehyde. The aqueous solution of Pd(0)(TPPTS)n could be reused without deterioration of the catalyst in the first and second recycling. The system proved to be efficient with primary and secondary allylic substrates. The stereochemical outcome of the allylation through umpolung of allylpalladium, was also studied using models with a restraint conformation.