Palladium Enolate Umpolung: Cyclative Diacetoxylation of Alkynyl Cyclohexadienones Promoted by a Pd/SPRIX Catalyst
作者:Kazuhiro Takenaka、Suman C. Mohanta、Hiroaki Sasai
DOI:10.1002/anie.201311172
日期:2014.4.25
A novel palladium‐catalyzed reaction involving an unusual nucleophilic attack on a palladiumenolate was developed using a spiro‐bis(isoxazoline) (SPRIX) ligand. Treatment of alkynylcyclohexadienone substrates with a Pd/SPRIXcatalyst in acetic acid under an oxygen atmosphere furnished diacetoxylated benzofuranone derivatives in good yields. This cyclativediacetoxylation proceeded enantioselectively
Enantioselective Nickel-Catalyzed <i>anti</i>-Carbometallative Cyclizations of Alkynyl Electrophiles Enabled by Reversible Alkenylnickel <i>E</i>/<i>Z</i> Isomerization
作者:Christopher Clarke、Celia A. Incerti-Pradillos、Hon Wai Lam
DOI:10.1021/jacs.6b04206
日期:2016.7.6
Nickel-catalyzedadditions of arylboronic acids to alkynes, followed by enantioselective cyclizations of the alkenylnickel species onto tethered ketones or enones, are reported. These reactions are reliant upon the formal anti-carbonickelation of the alkyne, which is postulated to occur by the reversible E/Z isomerization of an alkenylnickel species.
Mn-catalyzed radical initiated domino transformation of alkynylated cyclohexadienones with TMSN<sub>3</sub> and O<sub>2</sub> to bicyclic azido alcohols
作者:Pranesh Pal、Prathama S. Mainkar、Kiranmai Nayani、Srivari Chandrasekhar
DOI:10.1039/d0cc00102c
日期:——
alkyne-tethered cyclohexadienones with TMSN3 under mild conditions is reported. This domino reaction presents good diastereoselectivity generating bicyclic azido alcohol scaffolds which can be transformed into usefulbuildingblocks in organic synthesis for medicinal chemistry.
Silver(I)-Catalyzed Enyne Cyclization/Aromatization of Alkyne-Tethered Cyclohexadienones to Access Meta-Substituted Phenols
作者:Anandarao Munakala、Rambabu Chegondi
DOI:10.1021/acs.orglett.0c03819
日期:2021.1.15
Herein we report a highly regioselective silver(I)-catalyzed intramolecular annulation of alkyne-tethered cyclohexadienones to access meta-substituted phenols with enone functionality, which are difficult to synthesize from conventional methods. The reaction proceeds via intramolecular 1,6-enyne cyclization followed by aromatization and subsequent oxetene ring rearrangement. This strategy has also
Lewis Acid-Driven Meyer–Schuster-Type Rearrangement of Yne-Dienone
作者:Rajendra K. Mallick、Srinivas Vangara、Nagarjuna Kommu、Tirumaleswararao Guntreddi、Akhila K. Sahoo
DOI:10.1021/acs.joc.1c00290
日期:2021.5.21
The reaction involves an uncommon 5-exo-trig 1,6-enyne cyclization of alkyne-tethered-cyclohexadienone, aromatization-triggered C–O bond cleavage, and an electrocyclic 4π-ring-opening of oxetene intermediate. This atom-efficient transformation provides access to a wide range of synthetically important α-(m-substituted phenol)-α,β-unsaturated ketones, featuring a broad scope with labile functional group