Transition Metal-Catalyzed Radical Cyclizations: A Low-Temperature Process for the Cyclization of N-Protected N-Allyltrichloroacetamides to Trichlorinated γ-Lactams and Application to the Stereoselective Preparation of β,γ-Disubstituted γ-Lactams

Hideo Nagashima, Nobuyasu Ozaki, Masayuki Ishii, Koji Seki, Masayoshi Washiyama, Kenji Itoh

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129 Citations (Scopus)

Abstract

Cyclizations of N-substituted N-allyltrichloroacetamides, where the substituent is an alkyl, Cbz, Boc, Ts, or Ms group, are catalyzed by a 1:1 mixture of CuCl and bipyridine to give the corresponding β,γ-trichlorinated γ-lactams in high yields. The reactions proceed at temperatures from −78 °C to room temperature. Cyclizations of N-allyltrichloroacetamides of acyclic secondary allylic amines are achieved with good selectivity; the cis/trans ratios of the γ-lactams formed were dependent on the substituents on the nitrogen atom. The stereochemical outcome is compared with that of free-radical cyclization.

Original languageEnglish
Pages (from-to)464-470
Number of pages7
JournalJournal of Organic Chemistry
Volume58
Issue number2
DOIs
Publication statusPublished - Jan 1 1993

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Lactams
Cyclization
Transition metals
Temperature
Free Radicals
Amines
Nitrogen
Atoms

All Science Journal Classification (ASJC) codes

  • Organic Chemistry

Cite this

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title = "Transition Metal-Catalyzed Radical Cyclizations: A Low-Temperature Process for the Cyclization of N-Protected N-Allyltrichloroacetamides to Trichlorinated γ-Lactams and Application to the Stereoselective Preparation of β,γ-Disubstituted γ-Lactams",
abstract = "Cyclizations of N-substituted N-allyltrichloroacetamides, where the substituent is an alkyl, Cbz, Boc, Ts, or Ms group, are catalyzed by a 1:1 mixture of CuCl and bipyridine to give the corresponding β,γ-trichlorinated γ-lactams in high yields. The reactions proceed at temperatures from −78 °C to room temperature. Cyclizations of N-allyltrichloroacetamides of acyclic secondary allylic amines are achieved with good selectivity; the cis/trans ratios of the γ-lactams formed were dependent on the substituents on the nitrogen atom. The stereochemical outcome is compared with that of free-radical cyclization.",
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TY - JOUR

T1 - Transition Metal-Catalyzed Radical Cyclizations

T2 - A Low-Temperature Process for the Cyclization of N-Protected N-Allyltrichloroacetamides to Trichlorinated γ-Lactams and Application to the Stereoselective Preparation of β,γ-Disubstituted γ-Lactams

AU - Nagashima, Hideo

AU - Ozaki, Nobuyasu

AU - Ishii, Masayuki

AU - Seki, Koji

AU - Washiyama, Masayoshi

AU - Itoh, Kenji

PY - 1993/1/1

Y1 - 1993/1/1

N2 - Cyclizations of N-substituted N-allyltrichloroacetamides, where the substituent is an alkyl, Cbz, Boc, Ts, or Ms group, are catalyzed by a 1:1 mixture of CuCl and bipyridine to give the corresponding β,γ-trichlorinated γ-lactams in high yields. The reactions proceed at temperatures from −78 °C to room temperature. Cyclizations of N-allyltrichloroacetamides of acyclic secondary allylic amines are achieved with good selectivity; the cis/trans ratios of the γ-lactams formed were dependent on the substituents on the nitrogen atom. The stereochemical outcome is compared with that of free-radical cyclization.

AB - Cyclizations of N-substituted N-allyltrichloroacetamides, where the substituent is an alkyl, Cbz, Boc, Ts, or Ms group, are catalyzed by a 1:1 mixture of CuCl and bipyridine to give the corresponding β,γ-trichlorinated γ-lactams in high yields. The reactions proceed at temperatures from −78 °C to room temperature. Cyclizations of N-allyltrichloroacetamides of acyclic secondary allylic amines are achieved with good selectivity; the cis/trans ratios of the γ-lactams formed were dependent on the substituents on the nitrogen atom. The stereochemical outcome is compared with that of free-radical cyclization.

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