Synthetic Strategy for Cyclic Amines: A Stereodefined Cyclic N,O‐Acetal as a Stereocontrol and Diversity‐Generating Element

Abstract

Scheme 2. Examples for the use of cyclic N,O-acetals as a stereocontrol element. a) For dihydroxylation. b) For epoxidation. c) For hydrogenation. NMO = N-methylmorpholine-N-oxide, THF = tetrahydrofuran. Scheme 3. Examples for the use of cyclic N,O-acetals as a diversitygenerating element. TBS = tert-butyldimethylsilyl.

Acid‐Catalyzed Cascade Reaction of 4‐Aminobutanal Derivatives with (Hetero)aromatic Nucleophiles: A Versatile One‐Pot Access to 2‐(Hetero)arylpyrrolidines.

“…Based on these data, we have developed a one‐pot approach to 1‐sulfonyl‐2‐ethoxypyrrolidines 14 via a reaction of 4,4‐diethoxybutan‐1‐amine with various sulfonyl chlorides (Scheme ) . Notably, these compounds are valuable intermediates in the synthesis of various pyrrolidine derivatives …”

Triazole‐Linked Iminosugars and Aromatic Systems as Simplified UDP‐Galf Mimics: Synthesis and Preliminary Evaluation as Galf‐Transferase Inhibitors

“…However, while several examples of N ‐ and O ‐armed alkynyl iminosugars have been published, only one example of a 1‐ C ‐propargyl compound has been reported to date in the piperidine series (i.e., 1‐ C ‐propargyl‐1‐deoxyimino‐ d ‐xylitol) . A few examples based on a pyrrolidine core have been obtained by organocatalysis or through addition to cyclic N,O‐acetals or to cyclic nitrones …”

Access to trans‐3,4‐Dihydroxy‐2‐alkylpyrrolidines and Piperidines by Use of Stereodefined Cyclic N,O‐Acetals as a Diversity‐Generating Element

“…With regard to the stereoselectivity of the Lewis acid‐mediated carbon–carbon bond formation step, cis stereochemistry between C 2 and C 3 substituents was observed when the hydroxyl groups were protected with tert ‐butyldimethylsilyl (TBDMS) group 1a. From the viewpoint of controlling stereochemical diversity of the cyclic amine structure, we became interested in developing a synthetic method to generate diastereomeric trans‐ 3,4‐dihydroxy‐2‐alkyl‐pyrrolidines and piperidines 2.…”