Transition metal-catalyzed radical cyclizations: a low-temperature process for the cyclization of N-protected N-allyltrichloroacetamides to trichlorinated .gamma.-lactams and application to the stereoselective preparation of .beta.,.gamma.-disubstituted .gamma.-lactams
摘要:
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 beta,gamma-trichlorinated gamma-lactams in high yields. The reactions proceed at temperatures from -78-degrees-C to room temperature. Cyclizations of N-allyltrichloroacetamides of acyclic secondary allylic amines are achieved with good selectivity; the cis/trans ratios of the gamma-lactams formed were dependent on the substituents on the nitrogen atom. The stereochemical outcome is compared with that of free-radical cyclization.
Functional rearrangement of polychlorinated pyrrolidin-2-ones to 5-imino-lactams promoted by n-propylamine
作者:Chiara Danieli、Franco Ghelfi、Adele Mucci、Ugo M. Pagnoni、Andrew F. Parsons、Mariella Pattarozzi、Luisa Schenetti
DOI:10.1016/j.tet.2004.09.073
日期:2004.12
The reaction of 4-methyl-pyrrolidin-2-ones, chlorinated at the C(3) and C(6) positions, with n-propylamine constitutes a new method for the preparation of 5-propylimino-pyrrolidin-2-ones or 3-pyrrolin-2-ones in generally good yields. The transformation involves a series of eliminations, substitutions and double bond shifts. This constitutes a remarkable example of a functional rearrangement.
Easy approach to 3-benzylimino-2-pyrrolidinones from 3-chloro-4-chloromethyl-2-pyrrolidinones
作者:Franco Ghelfi、Gianluca Ghirardini、Emanuela Libertini、Luca Forti、Ugo M. Pagnoni
DOI:10.1016/s0040-4039(99)01798-0
日期:1999.12
3-chloro-4-chloromethyl-2-pyrrolidinones, benzylamine and NaI in THF at 80°C. An endo-dehydrohalogenation followed by a SN2′ substitution on the intermediate allylchloride, and finally a shift of the exo-double bond to Δ3 with attendant tautomerization, appears to be the most probable reactionmechanism.
resulted in facile activation of their carbon-chlorine bond at the α-position. Addition of the carbon moiety and the chlorine atom to olefins furnished the carbon-carbonbond forming reaction at the α-position of the carbonyl group. In certain trichlorinated γ-lactams including a carbon-carbon double bond at an appropriate position, intramolecular addition reactions took place to give bicyclic lactams
Acyclic and alicyclic N-substituted halo-2-pyrrolidinones and their
申请人:Stauffer Chemical Company
公开号:US04069038A1
公开(公告)日:1978-01-17
Acyclic and alicyclic N-substituted halo-2-pyrrolidinones having the formula ##STR1## in which Q is oxygen or sulfur; R is lower alkyl, haloalkyl, alkenyl, cycloalkyl, cycloalkylalkyl, benzyl and chlorobenzyl; X is hydrogen or chlorine, Y is chlorine or bromine and Z is chlorine or bromine, provided that when R is allyl, Y and Z are each chlorine or bromine, and provided that when R is cyclohexyl, X is other than chlorine. The compounds of this invention are prepared by a novel process and are useful as herbicides.
Preparation of acyclic and alicyclic N-substituted halo-2-pyrrolidinones
申请人:Stauffer Chemical Company
公开号:US04119636A1
公开(公告)日:1978-10-10
Acyclic and alicyclic N-substituted halo-2-pyrrolidinones having the formula ##STR1## in which Q is oxygen or sulfur; R is lower alkyl, haloalkyl, alkenyl, cycloalkyl, cycloalkylalkyl, benzyl and chlorobenzyl; X is hydrogen or chlorine, Y is chlorine or bromine and Z is chlorine or bromine, provided that when R is allyl, Y and Z are each chlorine or bromine, and provided that when R is cyclohexyl, X is other than chlorine. The compounds of this invention are prepared by a novel process and are useful as herbicides.