- Total Synthesis of (+)-Erogorgiaene and the Pseudopterosin A?F Aglycone via Enantioselective Cobalt-Catalyzed Hydrovinylation
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Due to their pronounced bioactivity and limited availability from natural resources, metabolites of the soft coral Pseudopterogorgia elisabethae, such as erogorgiaene and the pseudopterosines, represent important target molecules for chemical synthesis. We have now developed a particularly short and efficient route towards these marine diterpenes exploiting an operationally convenient enantioselective cobalt-catalyzed hydrovinylation as the chirogenic step. Other noteworthy C?C bond forming transformations include diastereoselective Lewis acid-mediated cyclizations, a Suzuki coupling and a carbonyl ene reaction. Starting from 4-methyl-styrene the anti-tubercular agent (+)-erogorgiaene (>98 % ee) was prepared in only 7 steps with 46 % overall yield. In addition, the synthesis of the pseudopterosin A aglycone was achieved in 12 steps with 30 % overall yield and, surprisingly, was found to exhibit a similar anti-inflammatory activity (inhibition of LPS-induced NF-κB activation) as a natural mixture of pseudopterosins A?D or iso-pseudopterosin A, prepared by β-D-xylosylation of the synthetic aglycone.
- Movahhed, Sohajl,Westphal, Julia,Kempa, Alexander,Schumacher, Christian Eric,Sperlich, Julia,Neud?rfl, J?rg-Martin,Teusch, Nicole,Hochgürtel, Matthias,Schmalz, Hans-Günther
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supporting information
p. 11574 - 11579
(2021/07/02)
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- Yttrium phosphasalen initiators for rac-lactide polymerization
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A series of highly active yttrium phosphasalen initiators for the heteroselective ring-opening polymerization of rac-lactide are reported. The initiators are yttrium alkoxide complexes ligated by iminophosphorane analogues of the popular "salen" ligand, t
- Clare,Cao, Thi-Phuong-Anh,Le Goff, Xavier F.,Long, Nicholas J.,Auffrant, Audrey,Williams, Charlotte K.
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supporting information
p. 1475 - 1483
(2013/05/09)
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- Yttrium phosphasalen initiators for rac -lactide polymerization: Excellent rates and high iso-selectivities
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Highly active yttrium phosphasalen initiators for the stereocontrolled ring-opening polymerization of rac-lactide are reported. The initiators are coordinated by a new class of ancillary ligand: an iminophosphorane derivative of the popular "salen" ligand
- Bakewell, Clare,Cao, Thi-Phuong-Anh,Long, Nicholas,Le Goff, Xavier F.,Auffrant, Audrey,Williams, Charlotte K.
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supporting information
p. 20577 - 20580
(2013/02/23)
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- Organochalcogen substituents in phenolic antioxidants
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Little is known about the ED/EW character of organochalcogen substituents and their contribution to the O-H bond dissociation enthalpy (BDE) in phenolic compounds. A series of ortho- and para-(S,Se,Te)R-substituted phenols were prepared and investigated by EPR, IR, and computational methods. Substituents lowered the O-H BDE by >3 kcal/mol in the para position, while the ortho-effect was modest due to hydrogen bonding (~3 kcal/mol) to the O-H group.
- Amorati, Riccardo,Pedulli, Gian Franco,Valgimigli, Luca,Johansson, Henrik,Engman, Lars
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scheme or table
p. 2326 - 2329
(2010/07/20)
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- OXIDATIVE COUPLING REACTION OF 2-HALOPHENOLS WITH K3Fe(CN)6 IN BENZENE SOLUTION
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The oxidative coupling of twelve 2-halophenols (1a-1l) was carried out with K3Fe(CN)6 in benzene solution to obtain the corresponding dibenzofuran derivatives.However, only a small amount of the desired dibenzofurans such as 2,6-di-tert-butyl-8-methoxybenzofuran-1,4-quinone (9) and 4,8-di-tert-butyl-2,6-di-isopropyl-1-hydroxydibenzofuran (11) were obtained from 2-bromo-6-tert-butyl-4-methoxy- (1d) and 2-bromo-4-tert-butyl-6-isopropylphenol (1g), respectively.In the other cases, alternative type of products or tarry materials were formed.
- Tashiro, Masashi,Yoshiya, Haruo
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p. 653 - 660
(2007/10/02)
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