Intramolecular Diels–Alder reactions using chiral ruthenium Lewis acids and application in the total synthesis of ent-ledol
作者:Sirinporn Thamapipol、E. Peter Kündig
DOI:10.1039/c1ob06121f
日期:——
ligand BIPHOP-F and a Cp or an indenyl ‘roof’ can efficiently catalyze asymmetric intramolecular Diels–Alder reactions of trienes to form bicyclic adducts with good to excellent asymmetric induction. This reaction forms the key step in a totalsynthesis of ent-ledol in 96% ee. The synthesis also helps to clarify the stereochemical assignment of ledol and inconsistencies in the measured optical rotation
Diastereoselective Three-Component 3,4-Amino Oxygenation of 1,3-Dienes Catalyzed by a Cationic Heptamethylindenyl Rhodium(III) Complex
作者:Finn Burg、Tomislav Rovis
DOI:10.1021/jacs.1c09276
日期:2021.11.3
tool to rapidly access β-amino alcohols–a privilegedmotif ubiquitous in natural products, pharmaceuticals and agrochemicals. Although a variety of expedient methods are established for simple alkenes, selective amino oxygenation of 1,3-dienes is less explored. Within this context, methods for the oxyamination of 1,3-dienes that are selective for the internal position remain unprecedented. We herein report
Abstract The synthesis of α-chloro-tetrahydrophosphinines by inter- or intramolecular [4+2] cycloaddition reactions involving unstabilized phosphaalkenes is presented. Conditions for a selective base-induced isomerisation of substituted dihydrophosphinines are precised. A tautomeric phosphaalkene/vinylphosphine equilibrium was for the first time evidenced.
A Boron Alkylidene-Alkene Cycloaddition Reaction: Application to the Synthesis of Aphanamal
作者:Xun Liu、T. Maxwell Deaton、Fredrik Haeffner、James P. Morken
DOI:10.1002/anie.201705720
日期:2017.9.11
unusual net [2+2] cycloadditionreaction between boron alkylidenes and unactivated alkenes. This reaction provides a new method for the construction of carbocyclic ring systems bearing versatile organoboronic esters. Aside from surveying the scope of this reaction, we provide details about the mechanistic underpinnings of this process, and examine its application to the synthesis of the natural product
Palladium(II) Catalyzed C–H Functionalization Cascades for the Diastereoselective Synthesis of Polyheterocycles
作者:Michael S. Watt、Kevin I. Booker-Milburn
DOI:10.1021/acs.orglett.6b02947
日期:2016.11.4
C–H activation offers huge potential in the generation of complex structures from simple starting materials. Herein we report the development of a highly diastereoselective palladium(II) catalyzed C–H functionalization cascade to produce novel, unsaturated polyheterocycles from simple diene-tethered heterocyclic starting materials. The reaction is applicable to both indole and pyrrole based substrates