ChemInform Abstract: Asymmetric Diels‐Alder Reaction of Cyclopentadiene and Methyl Acrylate Catalyzed by Chiral Lewis Acids.

Abstract

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Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

“…All of them lead either to complete or to unselective reduction of the C=N and C=O bond. Thus, LiAlH 4 reduces the C=O and C=N group of 3 , and 3- exo -hydroxycamphorsultam is obtained in good yields [ 16 ]. Under Meerwein–Ponndorf–Verley conditions (Al(OiPr) 3 /iPrOH), a mixture of the 3-hydroxyimine, 3-oxocamphorsultam and 3- exo -hydroxycamphorsultam is produced.…”

“…This versatile intermediate can be reduced to provide a chelating ligand for chiral catalysis [16], or oxidised to oxaziridines used as efficient chiral oxidising reagents [13,17–19]. …”

“…From cheap camphor-10-sulfonic acid ( 1 ), a cyclic sulfonimide 2 can easily be obtained which is readily converted into useful auxiliaries [ 12 ], or oxidized to the oxoimide 3 ( Scheme 1 ) [ 13 – 15 ]. This versatile intermediate can be reduced to provide a chelating ligand for chiral catalysis [ 16 ], or oxidised to oxaziridines used as efficient chiral oxidising reagents [ 13 , 17 – 19 ].…”

Strecker degradation of amino acids promoted by a camphor-derived sulfonamide

“…On the other hand the C=N double bond can be converted into an oxaziridine group forming chiral oxaziridines which act as enantioselective oxidation reagents [ 1 , 3 – 5 ]. Other types of reactions include the alkylation of the imine nitrogen atom followed by ring annulation [ 6 ], cleavage of the sulfonimine [ 7 – 8 ] or camphor [ 9 ] rings, reduction of the CO or CN double bonds [ 10 ], addition of acetylide anions to form dialkynes that can undergo complex skeletal rearrangements and unusual redox reactions [ 11 – 14 ].…”