Gold(III) Porphyrin-Catalyzed Cycloisomerization of Allenones
摘要:
Gold(III) porphyrin-catalyzed cycloisomerization of allenones gave the corresponding furans in good to excellent yields (up to 98%) and with quantitative substrate conversions. By recovering the Au(III) catalyst, a recyclable catalytic system is developed with over 8300 product turnovers attained for the cycloisomerization of 1-phenyl-buta-2,3-dien-1-one. The versatility of the gold(Ill) porphyrin catalyst was exemplified by its application to the hydroamination and hydration of phenylacetylene in 73% and 87% yield, respectively.
Iodine-Initiated Domino Reaction of Hepta-1,2-dien-6-yn-4-ols and Brønsted Acid Promoted Cyclization of Hepta-1,2,6-trien-4-ols Leading to Functionalized Benzenes
作者:Yan He、Xin-Ying Zhang、Liang-Yan Cui、Xue-Sen Fan
DOI:10.1002/asia.201201151
日期:2013.4
carbonyl groups, along with the construction of the benzenoid core, has been achieved through an iodine‐initiated dominoreaction of hepta‐1,2‐dien‐6‐yn‐4‐ols. Moreover, cyclization of hepta‐1,2,6‐trien‐4‐ols turns out to also be an efficient pathway toward diversely substituted benzenes.
InI3- or ZnI2-Catalyzed Reaction of Hydroxylated 1,5-Allenynes with Thiols: A New Access to 3,5-Disubstituted Toluene Derivatives
作者:Jie Ma、Lingling Peng、Xiu Zhang、Zhe Zhang、Melody Campbell、Jianbo Wang
DOI:10.1002/asia.201000267
日期:——
undergo direct addition of the nucleophiles to the unsaturated bonds or trigger subsequent rearrangement reactions. This chemistry has witnessed increasing development in recent years. In this report, we have focused on the metal‐catalyzed reactions of a variety of substituted propargyl allenic alcohols and thiophenols using indium(III) and zinc(II) catalysts, which can activate both the alcohol and alkyne
C−C-Bond Formation by the Palladium-Catalyzed Cycloisomerization/Dimerization of Terminal Allenyl Ketones: Selectivity and Mechanistic Aspects
作者:A. Stephen K. Hashmi、Thorsten L. Ruppert、Thomas Knöfel、Jan W. Bats
DOI:10.1021/jo970837l
日期:1997.10.1
conditions, besides the normal functional group tolerance known for palladium-catalyzed reactions, an interesting selectivity was observed with functional groups that are known to react either in palladium-catalyzed reactions or reactions catalyzed by other transition-metals. Thus aryl halides, terminal alkynes, 1,6-enynes, and alpha-allenic alcohols were tolerated. In the latter example the selective reaction
Monohydrochloride Assisted Synthesis of Functionalized Isoxazoles and Pyrazoles from Allenic Ketones: First Synthesis of (<i>Z</i>
)-2-Methyl-7H-benzo[b]pyrazolo[5,1-d][1,5]oxazocines
作者:Debayan Sarkar、Sushree Ranjan Sahoo
DOI:10.1002/ejoc.201900008
日期:2019.3.14
A straight forward synthesis of substituted isoxazoles and pyrazoles from 1,2‐allenic ketones assisted by hydrochlorides of hydrazine and hydroxylamine is presented. In the process, the propyloxy‐phenyl pyrazoles were transformed to (Z)‐2‐methyl 7H benzo[b]pyrazolo[5,1‐d][1,5]oxazocines which are important and emissive compounds.
Revisiting the Addition of in-situ Nucleophiles to Allenic Ketones: An Entry Towards Synthesis of Benzodioxins
作者:Sushree Ranjan Sahoo、Debayan Sarkar
DOI:10.1002/ejoc.202000076
日期:2020.3.22
A revisit towards regioselective addition of in situ generated negative nucleophiles to allenicketones in the presence of a base. A direct ring annulation towards the benzodioxin skeleton synthesis has been developed. In the process, the obtained E‐vinyl kenones were readily transformed into sulfones and 2,5‐disubstituted oxazole.