- Palladium mediated one-pot synthesis of 3-aryl-cyclohexenones and 1,5-diketones from allyl alcohols and aryl ketones
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One-pot synthesis of Robinson annulated 3-aryl-cyclohexenones from allyl alcohols and ketones using palladium is reported. Long chain aliphatic or aryl substitutions at the C1 position of allyl alcohol result in the formation of 1,5-diketone products. This simple one-pot method avoids the use of highly electrophilic vinyl ketones.
- Samser, Shaikh,Biswal, Priyabrata,Meher, Sushanta Kumar,Venkatasubbaiah, Krishnan
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p. 1386 - 1394
(2021/02/27)
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- Synthesis of chiral seven-membered β-substituted lactams: Via Rh-catalyzed asymmetric hydrogenation
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Rh/bisphosphine-thiourea ligand (ZhaoPhos)-catalyzed asymmetric hydrogenation of seven-membered β-substituted α,β-unsaturated lactams was successfully developed to prepare various chiral seven-membered β-substituted lactams with good to excellent results (up to >99% conversion, 99% yield, and >99% ee).
- Huang, Yi,Li, Pan,Dong, Xiu-Qin,Zhang, Xumu
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supporting information
p. 8819 - 8823
(2018/11/30)
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- Fe2(CO)9-mediated [5+1] cycloaddition of vinylcyclopropanes and CO for the synthesis of α, β-cyclohexenones
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A Fe2(CO)9-mediated [5+1] cycloaddition of vinylcyclopropanes (VCPs) and CO to α, β-cyclohexenones has been developed. The reaction can tolerate aryl and aliphatic groups at the α-position of VCPs, while VCP substrates with vinyl or alkynyl substitutions are not suitable ones. In addition, this reaction can also be used to synthesize bicyclic rings if an aryl group is attached to the vinyl moiety of the substrate. Compared to the Fe(CO)5-mediated [5+1] reaction, the use of cheap and safe Fe2(CO)9 and abandoning the photo-irradiation conditions are the two major advantages of the present method.
- Liu, Cheng-Hang,Zhuang, Zhe,Bose, Sritama,Yu, Zhi-Xiang
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supporting information
p. 2752 - 2755
(2016/05/19)
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- Isopropylmagnesium chloride-promoted unilateral addition of Grignard reagents to β-diketones: One-pot syntheses of β-tertiary hydroxyl ketones or 3-substituted cyclic-2-enones
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The regioselective unilateral additions of Grignard reagents to acyclic or cyclic β-diketones were effectively promoted by sub-stoichiometric amounts of i-PrMgCl to afford β-tertiary hydroxyl ketones or 3-substituted cyclic-2-enones, respectively. Also, the addition of Grignard reagents to acyclic β-diketones followed by a reaction with cyclic β-diketones in a one-pot process was put forward. The reaction mechanism was discussed in detail to explain the high regioselectivity via chemical experiments, hydrogen-deuterium exchange and mass spectrometry.
- Yuan, Rui,Zhao, Dan,Zhang, Li-Yuan,Pan, Xiang,Yang, Yan,Wang, Pei,Li, Hong-Feng,Da, Chao-Shan
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supporting information
p. 724 - 728
(2016/01/12)
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- Copper/Selectfluor-System-Catalyzed Dehydration-Oxidation of Tertiary Cycloalcohols: Access to β-Substituted Cyclohex-2-enones, 4-Arylcoumarins, and Biaryls
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A route to β-substituted cyclohex-2-enones, 4-arylcoumarins, and biaryls has been developed. This approach involves a one-pot Cu0/Selectfluor-catalyzed dehydration-oxidation of tertiary cycloalcohols. Thus, by using 2 equiv. of Selectfluor at 25 C, the dehydration-oxidation of tertiary cyclohexanols and oxabenzocyclohexanols gave β-substituted cyclohex-2-enones and 4-arylcoumarins, respectively; whereas the dehydration-oxidation of tertiary cyclohexanols gave biaryls as the final products by using 2.5 equiv. of Selectfluor at 80 C. A route to β-substituted cyclohex-2-enones, 4-arylcoumarins, and biaryls has been developed. This approach involves a one-pot Cu0/Selectfluor-catalyzed dehydration-oxidation of tertiary cycloalcohols.
- Ren, Shaobo,Zhang, Jian,Zhang, Jiahui,Wang, Heng,Zhang, Wei,Liu, Yunkui,Liu, Miaochang
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supporting information
p. 5381 - 5388
(2015/08/24)
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- Palladium-catalyzed oxidative heck coupling of cyclic enones with simple arenes by C-H activation
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A simple catalyst system consisting of Pd(OAc)2 and 3-nitropyridine for the aerobic oxidative Heck coupling of cyclic enones, in particular challenging unsubstituted cyclic enones, with simple arenes by C-H activation was investigated. This novel method was applied to various functionalized arenes and cyclic enones and allowed the synthesis of β-aryl cyclic enones in modest to high yields.
- Chung, Leung Gulice Yiu,Juwaini, Nur Asyikin Binte,Seayad, Jayasree
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p. 1270 - 1274
(2015/04/27)
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- Highly enantioselective synthesis of chiral cyclic allylic amines via RH-catalyzed asymmetric hydrogenation
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Highly regioselective and enantioselective asymmetric hydrogenation of cyclic dienamides catalyzed by an Rh-DuanPhos complex has been developed, which provides a readily accessible method for the synthesis of chiral cyclic allylic amines in excellent enantioselectivities (up to 99% ee). The products are valuable chiral building blocks and could be easily transformed to multisubstituted cyclohexane derivatives.
- Zhou, Ming,Liu, Tang-Lin,Cao, Min,Xue, Zejian,Lv, Hui,Zhang, Xumu
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supporting information
p. 3484 - 3487
(2014/07/21)
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- Ligand- and base-free Pd(II)-catalyzed controlled switching between oxidative heck and conjugate addition reactions
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A simple change of solvent allows controlled and efficient switching between oxidative Heck and conjugate addition reactions on cyclic Michael acceptor substrates, catalyzed by a cationic Pd(II) catalyst system. Both reactions are ligand- and base-free and tolerant of air and moisture, and the controlled switching sheds light on some of the factors which favor one reaction over the other.
- Walker, Sarah E.,Boehnke, Julian,Glen, Pauline E.,Levey, Steven,Patrick, Lisa,Jordan-Hore, James A.,Lee, Ai-Lan
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supporting information
p. 1886 - 1889
(2013/06/04)
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- Rh(I)-catalyzed [5 + 1] cycloaddition of vinylcyclopropanes and CO for the synthesis of α,β- and β,γ-cyclohexenones
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A cationic Rh(I)-catalyzed [5 + 1] cycloaddition of vinylcyclopropanes and CO has been developed, affording either β,γ-cyclohexenones as major products or α,β-cyclohexenones exclusively, under different reaction conditions.
- Jiang, Guo-Jie,Fu, Xu-Fei,Li, Qian,Yu, Zhi-Xiang
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supporting information; experimental part
p. 692 - 695
(2012/03/26)
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- Palladium-catalyzed Mizoroki-Heck-type reaction of aryl trimethoxysilanes
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A palladium-catalyzed Mizoroki-Heck-type reaction of aryl trimethoxysilanes with olefins is described. A series of ArSi(OMe)3 and olefins, including electron-rich and electron-deficient analogues worked well in the procedure, affording the arylation products in moderate to good yields. Georg Thieme Verlag Stuttgart.
- Ye, Zhishi,Chen, Fan,Luo, Fang,Wang, Wenhui,Lin, Baoda,Jia, Xiaofei,Cheng, Jiang
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supporting information; experimental part
p. 2198 - 2200
(2011/03/19)
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- Two methods for the preparation of 2-cyclohexenones from resin-bound 1,3-cyclohexanedione
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The addition of organolithium or Grignard reagents to viny]ogous ester resin 1 followed by mild hydrolysis of product resins 2 provides 3-alkyl-2-cyclohexenones in high purity (>95%). Alternatively, conversion of 1 to vinyl triflate resin 4 followed by palladium-mediated couplings with aryl boronic acids and hydrolysis furnishes 3-ary]-2-cyclohexenones in lower yield, but exceptional purity.
- Fraley, Mark E.,Rubino, Robert S.
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p. 3365 - 3368
(2007/10/03)
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