Enantioselective photoconversion of pyridones into β-lactam derivatives in inclusion complexes with optically active host compounds

Toda, Fumio; Tanaka, Koichi

doi:10.1016/s0040-4039(00)80480-3

Cited by 39 publications

(8 citation statements)

References 6 publications

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“…Enantioselective photochemical cyclizations in TADDOL inclusion compounds. In addition to an electrocyclic valence isomerization to a cyclobutene derivative (a), [185] there occurs in this case a photoreaction in which a six-electron p system formally undergoes an electrocyclic reaction followed by a 1,3-sigmatropic hydrogen shift (Ninomiya cyclization). [176,177] Anilides of carboxylic acids are introduced in (b) and (c), [186±188] as is an enamine of 2-methylcyclohexan-1,3-dione (a vinylogous anilide) in (d), [189] and a 2-arylthiocyclohexenone (a derivative of 3,5,5-trimethylcyclohexan-1,2-dione) in (e).…”

Section: Enantioselective Photoreactions In Taddol Inclusion Compoundsmentioning

confidence: 99%

TADDOLs, Their Derivatives, and TADDOL Analogues: Versatile Chiral Auxiliaries

Seebàch

Beck

Heckel

2001

Angew. Chem. Int. Ed.

535

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Section: Enantioselective Photoreactions In Taddol Inclusion Compoundsmentioning

confidence: 99%

TADDOLs, Their Derivatives, and TADDOL Analogues: Versatile Chiral Auxiliaries

Seebàch

Beck

Heckel

2001

Angew. Chem. Int. Ed.

535

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“…Indeed, the classic photochemical valence isomerization that converts pyridone into azabicyclo[2.2.0]hexene leads to an enantiomerically pure product when the inclusion compound is made with TADDOL. 20 A similar photoisomerization reaction leads to N-methylhexahydro-4-carbazolones (15) from N-methyl-N-phenyl-3-amino-2cyclohexen-1-one derivatives (16) (eq 6) 21 and βlactam derivatives (17) from 2-(N-acyl-N-alkylamino)cyclohex-2-enones (18) in inclusion crystals with TADDOL (eq 7). 22…”

Section: Selective Transformations In Taddol Inclusionmentioning

confidence: 99%

“…40 The chiral phosphite P,N-ligand derived from (+)-N-methylephedrine (33b) has also proven adequate for this reduction reaction, providing ee's of up to 94%. 41 (20) TADDOL-derived phosphoramidites (34) (R 1 ,R 2 = Me, c-C 4 H 8 , c-C 5 H 10 ) have been found to be the most efficient ligands in the enantioselective Rh-catalyzed [2 + 2 + 2] cycloadditions of alkenyl isocyanates (43) and terminal alkynes (44) (eq 21). This reaction has been applied to the total synthesis of (+)-lasubine II.…”

mentioning

confidence: 99%

(−)-(4R,5R)-4,5-Bis[hydroxy(diphenyl)methyl]-2,2-dimethyl-1,3-dioxolane

Simón‐Fuentes

Losada

2008

Encyclopedia of Reagents for Organic Synthesis

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“… Enantioselective photochemical cyclizations in TADDOL inclusion compounds. In addition to an electrocyclic valence isomerization to a cyclobutene derivative (a),185 there occurs in this case a photoreaction in which a six‐electron π system formally undergoes an electrocyclic reaction followed by a 1,3‐sigmatropic hydrogen shift (Ninomiya cyclization). 176, 177 Anilides of carboxylic acids are introduced in (b) and (c),186–188 as is an enamine of 2‐methylcyclohexan‐1,3‐dione (a vinylogous anilide) in (d),189 and a 2‐arylthiocyclohexenone (a derivative of 3,5,5‐trimethylcyclohexan‐1,2‐dione) in (e) 190.…”

Section: Inclusion Compounds Based On Taddolsmentioning

confidence: 99%

Prevention of type 2 diabetes: the Finnish experience

Härmä-Rodriquez

2007

European Diabetes Nursing

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TADDOLs, which contain two adjacent diarylhydroxymethyl groups in a trans relationship on a 1,3‐dioxolane ring, can be prepared from acetals or ketals of tartrate esters by reaction of the latter with aromatic Grignard reagents. They are extraordinarily versatile chiral auxiliaries. Here, a historical review of the subject is followed by discussion of the preparation of TADDOLs and analogous systems, including TADDOLs with N‐, P‐, O‐, and S‐heteroatom ligands appropriate for metals. Crystal structure analysis reveals that the heteroatoms on the diarylmethyl groups are almost always in close proximity to each other, joined together by H‐bonds, and predisposed to form chelate complexes in which the metallic centers reside in propeller‐like chiral environments. Applications of TADDOL derivatives in enantioselective synthesis extend from utilization as stoichiometric chiral reagents or in Lewis acid mediated reactions, to roles in catalytic hydrogenation and stereoregular metathesis polymerization. Derivatives and complexes based on the following metals have so far been investigated: Li, B, Mg, Al, Si, Cu, Zn, Ce, Ti, Zr, Mo, Rh, Ir, Pd, Pt. The number of stereoselective reactions already accomplished with TADDOLs is correspondingly large. It is also easy to prepare TADDOL derivatives that are readily polymerizable and graftable, and to transform them into immobilized solid‐phase catalysts. The result is catalysts, simply or dendritically immobilized in polystyrene or on silica gel and characterized by unexpected stability even after multiple use in titanium TADDOLate mediated reactions. TADDOLs show further unusual characteristics that make them useful for applications in material science and supramolecular chemistry: they are the most effective doping agents known for phase transformations of achiral (nematic) into chiral (cholesteric) liquid crystals. The TADDOL OH group that is not involved in intramolecular H‐bonding shows a strong tendency to associate intermolecularly with H‐bond acceptors. In the process of crystallization this leads, enantioselectively, to the formation of inclusion compounds that lend themselves to the separation of racemic mixtures not otherwise suited to the classical method of crystallization through diastereomeric salts. The high melting points of TADDOLs even make possible the resolution of racemates by distillation! Host–guest compounds formed between TADDOLs and achiral partners can serve as platforms for enantioselective photoreactions. It seems safe to predict that many more applications will be discovered for the TADDOLs and their derivatives.

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Enantioselective photoconversion of pyridones into β-lactam derivatives in inclusion complexes with optically active host compounds

Cited by 39 publications

References 6 publications

TADDOLs, Their Derivatives, and TADDOL Analogues: Versatile Chiral Auxiliaries

TADDOLs, Their Derivatives, and TADDOL Analogues: Versatile Chiral Auxiliaries

(−)-(4R,5R)-4,5-Bis[hydroxy(diphenyl)methyl]-2,2-dimethyl-1,3-dioxolane

Prevention of type 2 diabetes: the Finnish experience

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