A Stereodivergent Approach to (−)-α-Kainic Acid and (+)-α-Allokainic Acid Utilizing the Complementarity of Alkyne and Allene Cyclizations

Chevliakov, Maxim V.; Montgomery, John

doi:10.1021/ja993069j

Cited by 111 publications

(60 citation statements)

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“…A metallacycle-based mechanism involving intermediates 64 a and 64 b was proposed for these processes in direct analogy to the proposals made in the corresponding enone/alkyne and aldehyde/alkyne couplings (Sections 4.1 and 4.4). These processes were first reported by our group in the total syntheses of kainic acid (Section 5.1) [50] and testudinariol A (Section 5.6), [51] and more extensive methodology studies of the allene/aldehyde cyclization process were concurrently developed by Kang and Yoon [52] and by us. [53] It was demonstrated that both aldehydes and ketones participate in the cyclization process as do monosubstituted and 1,3-disubstituted allenes (Scheme 36).…”

Section: Coupling Of Alkenes or Carbonyl Compounds With Allenesmentioning

confidence: 99%

“…Kainic acid was prepared by the nickel-catalyzed cyclization of allene 81 with dimethylzinc (Scheme 44). [50] This key cyclization directly assembled the pyrrolidine nucleus and set the relative stereochemistry about the five-membered ring. The epimeric structure allokainic acid was prepared by the nickel-catalyzed cyclization of alkyne 82 with dimethylzinc, followed by a Tsuji rearrangement to install the C4 stereocenter (Scheme 45).…”

Section: Kainoid Amino Acidsmentioning

confidence: 99%

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Nickel‐Catalyzed Reductive Cyclizations and Couplings

2004

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For over 50 years, nickel catalysis has been applied in cycloaddition processes. Nickel-catalyzed reductive couplings and cyclizations, however, have only recently attracted a high level of interest. This group of new reactions allows a broad range of multicomponent couplings involving two or more pi components with a main-group or transition-metal reagent. These processes allow the assembly of important organic substructures from widely available reaction components. Multiple contiguous stereocenters, polycyclic ring systems, and novel arrays of complex functionality may often be prepared from simple, achiral, acyclic precursors. With three or more reactive functional groups participating in the catalytic processes, many mechanistic questions abound, including the precise timing of bond constructions and the nature of reactive intermediates. This Review is thus aimed at providing a critical evaluation of recent progress in this rapidly developing field.

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Section: Coupling Of Alkenes or Carbonyl Compounds With Allenesmentioning

confidence: 99%

Section: Kainoid Amino Acidsmentioning

confidence: 99%

Nickel‐Catalyzed Reductive Cyclizations and Couplings

2004

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“…Thus, treatment of N-allenyl oxazolidinone 5.40 with 2MeLi/ZnCl 2 in the presence of Ni(cod) 2 and Ti(O-i-Pr) 4 directly and selectively affords the product with the identical stereochemistry to that of the natural product a-kainic acid (97:3) (Scheme 5.29) [51]. Addition of Active Methylene Compounds to 1,3-Dienes 1,3-Cyclohexadiene reacts with diethyl malonate in ethanol containing 50 mol% sodium ethoxide at room temperature using an Ni(0) complex prepared from Ni(II)(acac) 2 and Et 3 Al (Eq.…”

Section: 26mentioning

confidence: 99%

Reaction of Dienes and Allenes

Kimura

Tamaru

2005

Modern Organonickel Chemistry

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1,3-Butadiene and isoprene (2-methyl-1,3-butadiene) are among the most important building blocks both in the laboratory and in the chemical industry. 1,3-Butadiene (DH f ¼ þ26:1) and 1,2-butadiene (methylallene DH f ¼ þ38:8) are highly unsaturated and labile even toward relatively unreactive reagents, such as O 2 in air, and undergo polymerization during storage.Although the [4þ2]cycloaddition -the so-called Diels-Alder reaction -of butadiene to afford 4-vinylcyclohexene is a thermally permitted process, it only proceeds under harsh conditions (e.g., at 250 C under high pressure). In contrast, nickel complexes promote the [4þ2]cycloaddition under milder conditions (e.g., at 0 C under ambient pressure) [1]. Furthermore, the complexes even promote thermally forbidden [4þ4]cycloaddition and other reactions. Many other 1,3-dienes and allenes are also subject to dimerization, oligomerization, and polymerization under nickel catalysis, and hence serve as useful C4 and C3 carbon resources for a variety of organic syntheses.This chapter deals with recent developments in the nickel-catalyzed functionalizations of conjugated dienes and allenes, and incorporates the following topics: 1) dimerization and polymerization; 2) allylic and homoallylic alkylation of carbonyl compounds (dienes and allenes as nucleophiles); and 3) 1,2-and 1,4-addition reactions of reagents X-Y toward dienes and allenes. 5.1Dimerization and Polymerization of 1,3-Dienes Nickel complexes are extremely effective catalysts for the dimerization and polymerization of dienes. The catalytic reactions are described in Chapter 6, Section 6.4. The major subject of this section relates to the structures and reactivities of Ni(II)Á(butadiene) 2 complexes (the stoichiometric reactions) and recent developments in the field of polymerization.Modern Organonickel Chemistry. Edited by Y. Tamaru

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“…The nickel-mediated reaction was used as a strategy for the total synthesis of natural products, a-alokainic acid [77,78] and isodomoic acid G [79], and the synthesis of isogeissoschizine skeleton (Scheme 4.32) [80].…”

Section: Sequential Reaction With Enonesmentioning

confidence: 99%

Reaction of Alkynes

Ikeda

2005

Modern Organonickel Chemistry

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Since the earliest investigations represented by cycloaddition [1] and carboxylation [2], the nickel-catalyzed reactions of alkynes have been extensively studied by many research groups. This chapter highlights recent developments in the nickelcatalyzed reactions of alkynes. Recent advancements in cycloaddition and the carboxylation of alkynes are described in Chapters 6 and 7, respectively.The most extensively studied reaction is the addition reaction of an AaB species (e.g., HaH, H-metals, metals-metals, CaH, and C-metals, where metals ¼ Si, Sn, B, etc.) to alkynes (Scheme 4.1). Generally, the addition of an AaB species to alkynes starts with oxidative addition of the AaB species to a nickel(0) complex to generate an AaNiaB species (see Section 1.7.1). The insertion of an alkyne into either the AaNi or the BaNi bond gives the alkenylnickel intermediate(s), which undergo reductive elimination to produce the alkenes functionalized with an A and B functionalities at the 1,2-positions (see Section 1.7.4). The A and B groups are usually introduced on the same face of alkynes, and cis-alkenes with respect to A and B are produced. When an AaB is CaX (X ¼ halogens, O, N), the alkenylnickel X intermediates are capable of undergoing, instead of reductive elimination, Modern Organonickel Chemistry. Edited by Y. Tamaru

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A Stereodivergent Approach to (−)-α-Kainic Acid and (+)-α-Allokainic Acid Utilizing the Complementarity of Alkyne and Allene Cyclizations

Cited by 111 publications

References 58 publications

Nickel‐Catalyzed Reductive Cyclizations and Couplings

Nickel‐Catalyzed Reductive Cyclizations and Couplings

Reaction of Dienes and Allenes

Reaction of Alkynes

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