- Diastereoselective Addition of Organometallic Reagents to Imines or Hydrazones Containing 1,3-Oxathiane As a Chiral Template
-
The addition of organometallic reagents to imines or hydrazones containing 1,3-oxathiane as a chiral auxiliary proceeded with high diastereoselectivity and can be used as a key reaction for the preparation of chiral β-amino alcohols.
- Matsubara, Seijiro,Ukita, Hideo,Kodama, Tomohiro,Utimoto, Kiitiro
-
-
Read Online
- Catalytic enantioselective synthesis of β-amino alcohols by nitrene insertion
-
Chiral β-amino alcohols are important building blocks for the synthesis of drugs, natural products, chiral auxiliaries, chiral ligands and chiral organocatalysts. The catalytic asymmetric β-amination of alcohols offers a direct strategy to access this class of molecules. Herein, we report a general intramolecular C(sp3)-H nitrene insertion method for the synthesis of chiral oxazolidin-2-ones as precursors of chiral β-amino alcohols. Specifically, the ring-closing C(sp3)-H amination of N-benzoyloxycarbamates with 2 mol% of a chiral ruthenium catalyst provides cyclic carbamates in up to 99% yield and with up to 99% ee. The method is applicable to benzylic, allylic, and propargylic C-H bonds and can even be applied to completely non-activated C (sp3)-H bonds, although with somewhat reduced yields and stereoselectivities. The obtained cyclic carbamates can subsequently be hydrolyzed to obtain chiral β-amino alcohols. The method is very practical as the catalyst can be easily synthesized on a gram scale and can be recycled after the reaction for further use. The synthetic value of the new method is demonstrated with the asymmetric synthesis of a chiral oxazolidin-2-one as intermediate for the synthesis of the natural product aurantioclavine and chiral β-amino alcohols that are intermediates for the synthesis of chiral amino acids, indane-derived chiral Box-ligands, and the natural products dihydrohamacanthin A and dragmacidin A.[Figure not available: see fulltext.].
- Zhou, Zijun,Tan, Yuqi,Shen, Xiang,Ivlev, Sergei,Meggers, Eric
-
p. 452 - 458
(2020/12/31)
-
- Synthesis and Inhibitory Mechanisms of Phospholipase A2 Inhibitors
-
Two types of Phospholipase A2 (PLA2) inhibitor were synthesized, one of which was a terpenoid having unsaturated aldehyde, and the other was a cyclic phospholipid analog. The inhibitory mechanisms of each compound were proposed. Thus, the former may irreversibly modify an interfacial recognition site, and the latter competitively binds to the catalytic site of PLA2 with the mode similar to that of the genuine substrate.
- Katsumura,Iwama,Inagaki,Fujii,Ikeda
-
p. 225 - 229
(2007/10/03)
-
- A new route for protected amino alcohols from (R)-glycidol. Copper(I) mediated alkylation of 4-tosyloxymethyl-2-oxazolidinone
-
The reaction of (S)-4-tosyloxymethyl-2-oxazolidinone, which was synthesized from (R)-glycidol through (R)-4-benzoyloxymethyl-2-oxazolidinone, with various lithium dialkylcuprate(I)s in THF proceeded smoothly to afford the corresponding protected amino alcohol derivatives in good yield.
- Iwama,Katsumura
-
p. 3363 - 3365
(2007/10/02)
-