Asymmetric Transfer Hydrogenation of Functionalized Acetylenic Ketones
摘要:
A systematic study of the asymmetric transfer hydrogenations of functionalized acetylenic ketones and diketones has been completed, together with a total synthesis of (S,S)-(-)-yashabushidiol B. In several cases, excellent enantioselectivities and yields were achieved.
α-Nitro Ketone Synthesis Using <i>N</i>-Acylbenzotriazoles
作者:Alan R. Katritzky、Ashraf A. A. Abdel-Fattah、Anna V. Gromova、Rachel Witek、Peter J. Steel
DOI:10.1021/jo051231x
日期:2005.11.1
Readily available N-acylbenzotriazoles 2a−l (derived from a variety of aliphatic, (hetero)aromatic, and N-protected α-amino carboxylic acids) smoothly convert primary 3a−c and α-functionalized primary nitroalkanes 3d into the corresponding α-nitro ketones 5a−p in yields of 39−86% (average 63%).
Regiodivergent Hydration–Cyclization of Diynones under Gold Catalysis
作者:Marta Solas、Miguel A. Muñoz、Samuel Suárez-Pantiga、Roberto Sanz
DOI:10.1021/acs.orglett.0c02892
日期:2020.10.2
Skipped diynones, efficiently prepared from biomass-derived ethyl lactate, undergo a tandem hydration–oxacyclization reaction under gold(I) catalysis. Reaction conditions have been developed for a switchable process that allows selective access to 4-pyrones or 3(2H)-furanonesfrom the same starting diynones. Further application of this methodology in the total synthesis of polyporapyranone B was demonstrated
Preparation of <i>β</i>-Keto Esters and <i>β</i>-Diketones by C-Acylation/Deacetylation of Acetoacetic Esters and Acetonyl Ketones with 1-Acylbenzotriazoles
作者:Alan R. Katritzky、Zuoquan Wang、Mingyi Wang、Chavon R. Wilkerson、C. Dennis Hall、Novruz G. Akhmedov
DOI:10.1021/jo049274l
日期:2004.10.1
Acyl-, aroyl-, and heteroaroyl-acetic esters 6a−f and 8a−l are prepared by reactions of 1-acylbenzotriazoles 1a−k with acetoacetic esters 5 or 7a,b in the presence of sodium hydride followed by regioselective deacetylation. Similar C-acylation/deacetylation of acetylacetone and benzoylacetone affords β-diketones 10a−d and 13a−c, respectively.
Efficient Conversion of Carboxylic Acids into<i>N</i>-Acylbenzotriazoles<b />
作者:Alan R. Katritzky、Yuming Zhang、Sandeep K. Singh
DOI:10.1055/s-2003-42462
日期:——
An improved one-pot procedure for the preparation of N-acylbenzotriazoles involves mild reaction conditions and allows the preparation of several derivatives not accessible by the previously reported methods.
Gold-Catalyzed Oxidative Cyclization Involving Nucleophilic Attack to the Keto Group of α,α′-Dioxo Gold Carbene and 1,2-Alkynyl Migration: Synthesis of Furan-3-carboxylates
作者:Ali Wang、Mingduo Lu、Yuanhong Liu
DOI:10.1021/acs.orglett.1c02389
日期:2021.9.3
for the synthesis of functionalized furan-3-carboxylates based on gold-catalyzed oxidative cyclization of diynones with alcohols or water has been developed. Mechanisticstudies revealed that a rare nucleophilic attack to the carbonyl group of the α,α′-dioxo gold carbene instead of the carbene center and 1,2-alkynyl group migration were involved in this transformation. This method offers several advantages