trans-Hydroalumination/Alkylation: One-Pot Synthesis of Trisubstituted Allylic Alcohols
摘要:
Described herein is a method of stereoselective synthesis of trisubstituted allylic alcohols by alkylation of alkenyl alanates, formed in situ through treatment of propargyl alcohols with Vitride (Red-Al). This technique represents the first of its kind to feature a trans-hydrometalation, and is particularly effective for the formation of 1,4-dienes. Applications involving primary, secondary, and tertiary alcohols are discussed, as well as limitations regarding both alkyne and electrophile components.
Trialkylphosphine-Mediated Synthesis of 2-Acyl Furans from Ynenones
作者:Chao Xu、Stéphane Wittmann、Manuel Gemander、Venla Ruohonen、J. Stephen Clark
DOI:10.1021/acs.orglett.7b01533
日期:2017.7.7
A novel reaction for the synthesis of 2-acyl furans is reported. The reaction is believed to proceed by sequential addition of a trialkylphosphine to an ynenone, 5-exo-dig cyclization to form the furan, and oxidation of the resulting phosphonium ylide with molecular oxygen. Many common functional groups are tolerated during the reaction, and the products are obtained in good to excellent yield under
Syntheses of <i>Z</i>-Iodovinylfurans and 2-Acyl Furans via Controllable Cyclization of Ynenones
作者:Mengxue Li、Fang Yang、Ting Yuan、Haoyang Li、Jian Li、Zi-Sheng Chen、Kegong Ji
DOI:10.1021/acs.joc.9b01852
日期:2019.10.4
Z-iodovinylfurans and 2-acyl furans promoted by NIS via controllable cyclization of ynenones is reported. The reaction proceeded by sequential 5-exo-dig electrophilic cyclization to intermediate 2-(iodomethylene)-2H-furanium cation D, providing a range of synthetically valuable and useful trisubstituted furan derivatives 2 and 3 in moderate to excellent yields. This approach is metal-free, mild, and atom-economic,
Primary and Secondary Allyltitanium(IV) Reagents in Aldehyde Allylation II: Application to an Enantioselective Preparation of a C1-C7 Fragment of Spiramycin
A syntheticapproach to the eastern part of spiramycin, an important antibiotic compound, is described. Introduction of the side chain was first envisaged through a Hoppe aldehyde allylation. This reaction was carried outbetween an optically pure aldehyde 32 and a (′)-γ-alkoxy allyltitanium(IV) species derived from a primary γ-alkoxy allyl (diisopropyl)carbamate. Under kinetic resolution conditions
<i>trans</i>-Hydroalumination/Alkylation: One-Pot Synthesis of Trisubstituted Allylic Alcohols
作者:Neil F. Langille、Timothy F. Jamison
DOI:10.1021/ol0613721
日期:2006.8.1
Described herein is a method of stereoselective synthesis of trisubstituted allylic alcohols by alkylation of alkenyl alanates, formed in situ through treatment of propargyl alcohols with Vitride (Red-Al). This technique represents the first of its kind to feature a trans-hydrometalation, and is particularly effective for the formation of 1,4-dienes. Applications involving primary, secondary, and tertiary alcohols are discussed, as well as limitations regarding both alkyne and electrophile components.