Total synthesis of (±)-ageline a, a physiologically active constituent ofAgelas sponges

Asao, Kazuhiko; Iio, Hideo; Tokoroyama, Takashi

doi:10.1016/s0040-4039(01)93906-1

Cited by 34 publications

(8 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the ability of organozincs to tolerate esters and lactones makes it possible to develop a highly satisfactory procedure for the synthesis of heterofunctional terpenoids, such as mokupalide, via Pd-catalyzed homoallyl-alkenyl and homopropargylalkenyl coupling [75] (Scheme 1-22). Other natural products synthesized via the Pdcatalyzed alkylation with alkylzincs include casbene [76] (Scheme 1-23) and ageline A [77] (Scheme 1-24). (Q-3-Iodo-2-alken-1 -oh, readily obtainable from propargyl alcohols via either reduction with LiAlH, and related reagents [78] or Cu-catalyzed carbomagnesiation [79] can be cleanly alkylated with alkylzinc derivatives in the presence of Pd-phosphine catalysts [80,81] (Scheme 1-25).…”

Section: Palladium-catalyzed Cross-coupling Involving Alkyl Groups Wimentioning

confidence: 99%

Palladium‐ or Nickel‐Catalyzed Cross‐Coupling with Organometals Containing Zinc, Magnesium, Aluminum, and Zirconium

Negishi¹,

Liu²

1998

Metal‐Catalyzed Cross‐Coupling Reactions

View full text Add to dashboard Cite

The cross-coupling reaction of organometallic reagents with organic halides and related electrophiles represents one of the most straightforward methods for carbon-carbon bond formation (Scheme 1-1). Despite its inherent simplicity and significance, however, its synthetic utility was very limited until the mid-1960s. Mainly Grignard reagents and organolithiums were used in earlier examples. In such cases, organic halides are mostly limited to alkyl (C,3) halides. Furthermore, the use of organometals containing Mg and Li is often complicated and limited by their generally low chemoselectivity. Although advances in organocopper chemistry [l] over the past three decades have solved many of the difficulties associated with the use of Grignard reagents and organolithiums, a number of other problems have remained unsolved.In 1972, Kumada [2] and Corriu [3] independently reported that the reaction of Grignard reagents with alkenyl or aryl halides could be markedly catalyzed by Ni-phosphine complexes, e.g., Cl,Ni(PPh,),. Although many other transition-metal-catalyzed reactions of Grignard reagents with organic halides without the use of phosphines were known, the socalled Kharasch-type reactions [4], with the exception of the Cu-catalyzed procedures [5,6], were not well suited for cross-coupling due to various complications, including extensive cross-homo scrambling.The discovery of Pd-catalyzed cross-coupling was somewhat more subtle and evolutionary. During the 1975-1976 period, several groups of workers including the present authors' group published various results involving Pd-phosphine complexes. Thus, Cassar "71 reported the Pd-catalyzed cross-coupling reaction of aryl bromides and iodides with sodium acetylides generated in situ by mixing terminal alkynes with NaOMe in DMF (Scheme 1-2). The corresponding reaction using a Ni-phosphine complex did not proceed Catalytically. Similar reactions of alkynes, where the countercations in active species were most probably ammonium and/or Cu', were also reported by Heck [8] and Sonogashira [9] (Scheme 1-2).

show abstract

Section: Palladium-catalyzed Cross-coupling Involving Alkyl Groups Wimentioning

confidence: 99%

Palladium‐ or Nickel‐Catalyzed Cross‐Coupling with Organometals Containing Zinc, Magnesium, Aluminum, and Zirconium

Negishi¹,

Liu²

1998

Metal‐Catalyzed Cross‐Coupling Reactions

View full text Add to dashboard Cite

show abstract

“…The subsequent two-carbon extension to alkyne 4 required some optimization. Using lithium acetylide ethylenediamine complex (LAEDA) in DMSO [28][29] at ambient temperature gave the desired product 11 in only moderate yield of 42% (Table 1, entry 1). Changing the solvent to DMF (entry 2) slightly increased the yield of 11, whereas using HMPA 30 lowered the yield to 7% (entry 3).…”

Section: Resultsmentioning

confidence: 99%

Formal Synthesis of Actinoranone Using a Racemization-Free One-Pot Semipinacol Rearrangement/Wittig Reaction

Menger¹,

Christmann²

2018

Preprint

View full text Add to dashboard Cite

show abstract

“…have been described. Furthermore, agelasines A, B, C, D, E and (+) F have been successfully synthesised (Iio et al 1985;Asao et al 1989;Piers and Roberge 1992;Piers et al 1995;Utenova and Gundersen 2004;Bakkestuen et al 2005;Marcos et al 2005). Agelasines display a wide range of bioactivities, for example antimicrobial and cytotoxic effects (Fu et al 1998;Vik et al 2007).…”

Section: Discussionmentioning

confidence: 99%

Antifouling activity of the sponge metabolite agelasine D and synthesised analogs onBalanus improvisus

et al. 2008

View full text Add to dashboard Cite

This study reports a screening study for antifouling (AF) activity of the natural compound agelasine D isolated from marine sponges of the genus Agelas and 20 synthesised analogs of agelasines and agelasimines. Agelasine D, together with two of the analogs, ie AV1003A and AKB695, displayed a strong inhibitory effect on settlement of Balanus improvisus cypris larvae. Agelasine D had an EC50 value of 0.11 microM while the two analogs AV1033A and AKB695 had EC50 values of 0.23 and 0.3 microM, respectively. None of these three compounds affected larval mortality as was the case with several of the analogs tested. Moreover, the effect of AV1033A and AKB695 was reversible. When cyprids after 24 h exposure to the compounds were transferred to fresh seawater, the settlement frequency compared with the controls was completely recovered. The properties of the agelasine D analogs AV1003A and AKB695 make them highly attractive candidates as AF agents in future marine coatings.

show abstract

Total synthesis of (±)-ageline a, a physiologically active constituent ofAgelas sponges

Cited by 34 publications

References 17 publications

Palladium‐ or Nickel‐Catalyzed Cross‐Coupling with Organometals Containing Zinc, Magnesium, Aluminum, and Zirconium

Palladium‐ or Nickel‐Catalyzed Cross‐Coupling with Organometals Containing Zinc, Magnesium, Aluminum, and Zirconium

Formal Synthesis of Actinoranone Using a Racemization-Free One-Pot Semipinacol Rearrangement/Wittig Reaction

Antifouling activity of the sponge metabolite agelasine D and synthesised analogs onBalanus improvisus

Contact Info

Product

Resources

About