Lewis Acid-Catalyzed [4 + 2] Benzannulation between Enynal Units and Enols or Enol Ethers: Novel Synthetic Tools for Polysubstituted Aromatic Compounds Including Indole and Benzofuran Derivatives
作者:Naoki Asao、Haruo Aikawa
DOI:10.1021/jo060597m
日期:2006.7.1
enynals 1, including o-(alkynyl)benzaldehydes, and carbonyl compounds 2, such as aldehydes and ketones, in the presence of a catalytic amount of AuBr3 in 1,4-dioxane at 100 °C gave the functionalized aromaticcompounds 3 in high yields. Similarly, the AuBr3-catalyzed reactions of 1 with acetal compounds 5 afforded the corresponding aromaticcompounds 3 in good yields. On the other hand, when the reaction
AuBr<sub>3</sub>-Catalyzed [4 + 2] Benzannulation between an Enynal Unit and Enol
作者:Naoki Asao、Haruo Aikawa、Yoshinori Yamamoto
DOI:10.1021/ja0477367
日期:2004.6.23
es, and carbonylcompounds 2 in the presence of a catalytic amount of AuBr3 in 1,4-dioxane at 100 degrees C gave the functionalized aromaticcompounds 3 in high yields. The AuBr3-catalyzed formal [4 + 2] benzannulation proceeds most probably through the coordination of the triple bond of 1 to AuBr3, the formation of a pyrylium auric ate complex via the nucleophilic addition of the carbonyl oxygen atom
Gold film-catalysed benzannulation by Microwave-Assisted, Continuous Flow Organic Synthesis (MACOS)
作者:Gjergji Shore、Michael Tsimerman、Michael G Organ
DOI:10.3762/bjoc.5.35
日期:——
Methodology has been developed for laying down a thin gold-on-silver film on the inner surface of glass capillaries for the purpose of catalysing benzannulation reactions. The cycloaddition precursors are flowed through these capillaries while the metal film is being heated to high temperatures using microwave irradiation. The transformation can be optimized rapidly, tolerates a wide number of functional
Highly Selective Electrophile-Induced Cascade Reactions between<i>o</i>-Alkynylbenzaldehydes and Styrene Oxides Leading to the Formation of 1-Naphthyl Ketones
作者:Nitin T. Patil、Ashok Konala、Vipender Singh、Vaddu V. N. Reddy
DOI:10.1002/ejoc.200900809
日期:2009.10
for the synthesis of naphthalene derivatives through reaction of o-alkynylbenzaldehydes and styreneoxides in the presence of molecular iodine was developed. The reaction involves Meinwald rearrangement of styreneoxides to form the corresponding aryl acetaldehydes. The enol forms of aryl acetaldehydes might undergo [4+2] benzannulation reactions with iodinated benzopyrilium ions, formed in situ from