Asymmetric Synthesis of 3‐Substituted γ‐ and δ‐Sultams

Abstract

An efficient and flexible asymmetric synthesis of various 3-substituted γ-and δ-sultams is described. The key step is a diastereoselective nucleophilic 1,2-addition of various organocerium compounds to the CN double bond of ω-SAMP-hydrazonosulfonates. The resulting hydrazines were obtained in good to excellent diastereomeric excesses (de = 78 to Ն 96 %). Removal of the chiral auxiliary by reductive N,N-bond cleavage afforded the corresponding aminosulfonates without racemisation. Ester hydrolysis and subsequent treatment

N,N-Dialkylhydrazones in Organic Synthesis. From Simple N,N-Dimethylhydrazones to Supported Chiral Auxiliaries

“…196 The classical, diastereoselective, nucleophilic 1,2-addition of various organocerium compounds to the CdN double bond of ω-SAMP-hydrazonosulfonates 223 was used as the key step in a flexible asymmetric synthesis of various 3-substituted γ-and δ-sultams 226 (Scheme 42). 197 The resulting hydrazines were obtained in good to excellent diastereomeric excesses (de 78-96%). Removal of the chiral auxiliary by reductive (BH 3 /THF) N-N bond cleavage and reaction with chloroformate afforded the corresponding N-protected aminosulfonates 225 without racemization.…”

A summary of seven- and eight-membered ring sultam syntheses via three Michael addition reactions

“…Suitable synthetic methods for sultam derivative construction have already been reported [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. In this paper, three tandem reactions using oxa-, aza-, and thia-Michael additions to vinyl sulfonamides as key reaction steps to generate seven-and eight-membered ring -N,N-, -N,O-, and -N,Ssultams are described.…”

Diastereoselective Synthesis of Novel Pyrrolidine or Pyrrolizine-Fused Benzo-δ-sultams via 1,3-Dipolar Cycloadditions

“…Sultams have traditionally been synthesized via cyclization protocols such as the Pictet–Spengler [6a], and Friedel–Crafts , dianion alkylation , cyclization of aminosulfonyl chlorides , [3 + 2] cycloadditions , Diels–Alder , Heck , and other reactions . Recently, a number of transition metal catalyzed approaches to sultams have been reported, including the use of Pd , Au , Cu , and Rh .…”