Addition of Dithiols to Bis-Ynones: Development of a Versatile Platform for the Synthesis of Polyketide Natural Products
作者:Helen F. Sneddon、Matthew J. Gaunt、Steven V. Ley
DOI:10.1021/ol034248f
日期:2003.4.1
[reaction: see text] The conjugate addition of dithiols to bis-ynones generates a versatile masked 1,3,5-triketone platform. These functional units are useful intermediates for the synthesis of oxygen-containing heterocycles commonly found in polyketide natural products. The tetrahydropyranyl fragments of the marine macrolides Lyngbouilloside and Callipeltoside A have been synthesized with use of this
作者:Damian G. Dunford、David W. Knight、Robert C. Wheeler
DOI:10.3998/ark.5550190.0013.717
日期:——
Copper-catalysed cyclisations of β-hydroxyhomopropargylic sulfonamides can be carried out using copper(II) acetate in hot toluene to provide generally excellent yields of the corresponding pyrroles.
可以在热甲苯中使用乙酸铜 (II) 进行 β-羟基高炔丙基磺酰胺的铜催化环化,以提供通常极好的相应吡咯产率。
Catalytic Asymmetric Direct Henry Reaction of Ynals: Short Syntheses of (2S,3R)-(+)-Xestoaminol C and (−)-Codonopsinines
作者:Daisuke Uraguchi、Shinji Nakamura、Takashi Ooi
DOI:10.1002/anie.201004072
日期:——
Triple for all: Various optically active anti‐β‐nitro propargylic alcohols are synthesized by the catalytic stereoselective addition of nitroalkanes to ynals (the directHenryreaction of ynals). The utilization of the rich chemistry of carbon–carbon triple bond allows rapid access to three natural products.
N-Heterocyclic Carbene (NHC)-Catalyzed/Lewis Acid Mediated Conjugate Umpolung of Alkynyl Aldehydes for the Synthesis of Butenolides: A Formal [3+2] Annulation
作者:Jing Qi、Xingang Xie、Runfeng Han、Donghui Ma、Juan Yang、Xuegong She
DOI:10.1002/chem.201204386
日期:2013.3.25
Reverse to success! A new formal [3+2] annulation reaction combining alkynyl aldehydes and β,γ‐unsaturated α‐ketoesters has been disclosed by using a NHC‐catalyzed/Lewis acid mediated strategy. This cooperative catalysis strategy first allows the “allenolate” intermediate as a nucleophilic synthon at the β‐position to react with activated electrophilic reagents by an addition reaction as the key CC
NHC catalyzed enantioselective Coates-Claisen rearrangement: a rapid access to the dihydropyran core for oleuropein based secoiridoids
作者:Seenuvasan Vedachalam、Nithya Murugesh、Priyanka Chakraborty、Ramasamy Karvembu、Xue-Wei Liu
DOI:10.1039/c7nj04057a
日期:——
functionalized enantioselective dihydropyran core of secoiridoids using an N-heterocyclic carbene (NHC) catalyzed Coates-Claisen rearrangement mechanism. The key steps of the synthesis are (i) the highly enantioselective NHC catalyzed Coates-Claisen rearrangement for the dihydropyran core, (ii) the assembly of the target dihydropyran core structure of oleuropein from a highly diastereoselective exocyclic trans