[2+2] Cycloaddition of 1,3-Dienes by Visible Light Photocatalysis
作者:Anna E. Hurtley、Zhan Lu、Tehshik P. Yoon
DOI:10.1002/anie.201405359
日期:2014.8.18
[2+2] Photocycloadditions of 1,3‐dienes represent a powerful yet synthetically underutilized class of reactions. We report that visiblelight absorbing transition metal complexes enable the [2+2] cycloaddition of a diverse range of 1,3‐dienes. The ability to use long‐wavelength visiblelight is attractive because these reaction conditions tolerate the presence of sensitive functional groups that might
Benzyne 1,2,4-Trisubstitution and Dearomative 1,2,4-Trifunctionalization
作者:Jiarong Shi、Lianggui Li、Chunhui Shan、Zhonghong Chen、Liang Dai、Min Tan、Yu Lan、Yang Li
DOI:10.1021/jacs.1c04389
日期:2021.7.21
4-trifunctionalization of benzyne have been accomplished from sulfoxides bearing a penta-2,4-dien-1-yl moiety. These cascade transformations proceed through a benzyne insertion into the S═O bond and an uncommon regiospecific anionic [4,5]-sigmatropic rearrangement, furnishing a C–O, C–S, and C–C bond on the C1-, C2-, and C4-position of a benzene ring, respectively. This study showcases new cascade benzyne reaction
Base catalysed rearrangements involving ylide intermediates. Part 7. The rearrangements of allyl(pentadienyl)- and propynyl(pentadienyl)ammonium cations. The [5,4] sigmatropic rearrangement
作者:Trevor Laird、W. David Ollis、Ian O. Sutherland
DOI:10.1039/p19800002033
日期:——
The basecatalysedrearrangements of the cations (7), (17), (22), and (27) gave the enamines (9), (18), (23), and (28), which on hydrolysis yielded the aldehydes (10), (19), (24), and (29) respectively. The reactions are shown to be concerted [5,4] sigmatropic rearrangements proceeding via a nine-membered transition state involving 10π electrons. The basecatalysedrearrangements of the 3-phenylprop-2-ynyl
Gold(I)-Catalyzed Enantioselective [4 + 2]-Cycloaddition of Allene-dienes
作者:Ana Z. González、F. Dean Toste
DOI:10.1021/ol902622b
日期:2010.1.1
An enantioselective gold(I)-catalyzed intramolecular [4 + 2]-cycloaddition of allenes and dienes is reported. The reactions allow for the asymmetric synthesis of trans-hexahydroindenes and pyrrolidine products using C3-symmetric phosphitegold(I) and ortho-arylphosphoramiditegold(I) complexes as catalysts, respectively.
Enantioselective Synthesis of cis-Fused Cyclooctanoids via Rhodium(I)-Catalyzed [4 + 2 + 2] Cycloadditions
作者:Brendan C. Lainhart、Erik J. Alexanian
DOI:10.1021/acs.orglett.5b00267
日期:2015.3.6
o]-type cycloadditions offer efficient, atom-economical routes to diverse complexcarbocycles. Recently, such transformations have emerged as unique strategies for medium ring carbocyclesynthesis. Despite the important developments in this area, however, highly enantioselective [m + n + o]-type processes accessing medium ring carbocycles have yet to be developed. Herein, a rhodium-catalyzed [4 + 2 + 2]
催化多组分[ m + n + o ]型环加成化合物提供了高效,原子经济的途径,可通往各种复杂的碳环化合物。最近,这种转化已成为中环碳环合成的独特策略。尽管在该领域取得了重要进展,但是,高度对映选择性[ m + n + o进入中环碳环化合物的]型过程尚未开发。在本文中,报道了铑催化的烯丙二烯与丙二烯的[4 + 2 + 2]环加成反应,从而能够直接立体选择性地合成顺式融合的环辛烷类化合物。这些环加成成功地用于各种π组分,并证明了在[4 + 2 + 2]过程中高水平对映选择性的潜力。