TfOH-catalyzed tandem cyclopropane ring enlargement/C–C formation/etherification of alkynylcyclopropanes and 1,3-diketones to cyclobutane-fused dihydrofurans
作者:Siyu Ye、Zhi-Xiang Yu
DOI:10.1039/c0cc04283h
日期:——
A new type of TfOH-catalyzed tandem cyclopropane ring enlargement/CâC formation/etherification reaction between alkynylcyclopropanes and 1,3-diketones to cyclobutane-fused dihydrofurans is described. The reaction tolerates a range of aryl and alkyl substituents with moderate to good yields.
Trisulfur Radical Anion (S<sub>3</sub><sup>•–</sup>) Involved [1 + 2 + 2] and [1 + 3 + 1] Cycloaddition with Aromatic Alkynes: Synthesis of Tetraphenylthiophene and 2-Benzylidenetetrahydrothiophene Derivatives
作者:Jing-Hao Li、Qi Huang、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1021/acs.orglett.8b02066
日期:2018.8.3
S3•–-mediated [1 + 2 + 2] and [1 + 3 + 1] cycloaddition reactions of aromatic alkynes to give tetraphenylthiophene and 2-benzylidenetetrahydrothiophene derivatives via two C–S bond formations are developed. These two protocols provide new, simple, and straightforward strategies to construct tetraphenylthiophene and 2-benzylidenetetrahydrothiophene derivatives under transition-metal-free conditions
Gold(I)-Catalyzed Ring Expansions of Unactivated Alkynylcyclopropanes to (<i>E</i>)-2-Alkylidenecyclobutanamines in the Presence of Sulfonamides
作者:Siyu Ye、Zhi-Xiang Yu
DOI:10.1021/ol9028786
日期:2010.2.19
The ringexpansion of cyclopropane derivatives provides a powerful method to construct synthetically useful four-membered carbocycles. Herein, a new type of gold(I)-catalyzed ringexpansion of an unactivated alkynylcyclopropane/sulfonamide trapping strategy to (E)-2-alkylidenecyclobutanamines was described. The reaction tolerates a range of aryl and alkyl substituents with moderate to good yields.
Asymmetric α-Pentadienylation of Aldehydes with Cyclopropylacetylenes
作者:Min-Song Wu、Zhi-Yong Han、Liu-Zhu Gong
DOI:10.1021/acs.orglett.0c03466
日期:2021.2.5
cyclopropylacetylene and its derivatives as the pentadienylation reagent, an asymmetric regioselective asymmetric α-pentadienylation reaction of aldehydes is developed by cooperative catalysis of a chiral Pd(0) catalyst and a chiral Brønsted acid in the presence of a subschoichmetric amount of an achiral amine. α-Pentadienylated aldehydes are afforded with high yields and enantioselectivities as well as excellent