Inclusion crystallization

When a solution of 10a and 11 in ether was kept at room temperature for 12 h, a 2 1 inclusion complex of 10a and 11 was obtained as colorless prisms (m.p. 134-137 °C) in 72% yield. When a powdered mixture of the inclusion crystal and 7 was kept at room temperature in the solid state for 3 days, (+)-trans-1,2-dibromocyclohexane (12) of 12% ee was obtained in 56% yield by distillation of the reaction mixture [3]. Much more efficient enantioselective reactions in the solid state are described in Sect. 6. 

Dynamics in Organic Inclusion Crystals of Steroids and Primary Ammonium Salts 505... 

Toda, F. Isolation and Optical Resolution of Materials Utilizing Inclusion Crystallization, 140, 43-69(1987). 

Isolation and Optical Resolution of Materials Utilizing Inclusion Crystallization... 

Table 8. Optical resolutions of phosphorous compounds 27 and 28 by inclusion crystallization with (-)-26...

From these observations, we have noticed the similarity of the simple lattice inclusions to the more sophisticated assemblies of molecules (e.g. cyclodextrins 76 and proteins 78 where the formation of H-bonded loops was first detected and described. Conclusively the motive for the formation of simple inclusion crystals and of more complex associates between high and low molecular weight compounds, such as enzyme-substrate complexes, can be traced back to the same source. 

Variable-temperature ESR studies have revealed large magnetic bistabilities in thiadiazole-fused 1,3,2-dithiazolyl 32 <2001SM1767, 2001MI451, 2002MI064434>, the thiadiazolopyrazine-fused 1,3,2-dithiazolyl 34, but not with the benzothiadiazolo-fused 1,3,2-dithiazolyl 33 <2004JA8256>. ESR studies have also been performed on inclusion crystals of the bicyclic [ 1,2,5]thiadiazolo[3,4-z/][ 1,3,2]dithiazol-2-yl 32 in channels of perhydrotriphenylene and tris(o-phenylenedioxy)cyclotriphosphazene <2002MI432>. 

Similar irradiation of the 1 1 complex of tropolone ether 10b and host compound 8 led to photoproducts 11b (100% ee) and 12b (72% ee) in 12 and 14% yields, respectively. The authors interpreted these reactions as follows disrotatory electrocyclic closure of tropolone derivative 10 to afford photoproduct 11 in the inclusion crystals occurs in only one direction owing to the steric hindrance of host 8. This interpretation appeared to be reasonable based on an examination of the X-ray crystal structure study of the inclusion complex [18]. Formation of keto-ester 12 takes place by a more complex mechanism... 

Hosomi H, Ohba S, Tanaka K, Toda F (2000) The first in situ observation of intramolecular rotation and cyclization of anilide by an X-ray study partial single-crystal to single-crystal photocyclization of A-methyl-A- ( )-methylmethacrolyl anilide in inclusion crystals. J Am Chem Soc 122 1818-1819... 

Lachwa, J. et al.. Condensed phase behaviour of ionic liquid-benzene mixtures congruent melting of a [emim][NTf2] C H inclusion crystal, Chem. Commun., 2445,2006. 

Scheme 3 illustrates intriguing enantioselection in organic reactions that proceed in chiral crystalline lattices (5). When inclusion crystals of a ketone and an optically active diol host are treated with BH3-ethyl-enediamine complex, the optically active alcohol is obtained in... 

If209 is crystallized at 213 K from ethyl acetate saturated with argon, inclusion crystals are formed which contain Ar atoms in one of the two types of octahedral holes in the close-... 

FIGURE 26. Molecular packing of the inclusion crystal of 209 and argon at 103 K. Positions of Ar atoms are marked by circles. Projection down the c axis. Reproduced by permission of VCH VerlagsgesellschaftmbH from Reference 322... 

Keywords chalcone, dibenzylidene acetone, inclusion crystal, [2+2]photo-cycloaddition, cyclobutane... 

Keywords tropolone alkyl ether, inclusion crystal, [2+24]photocycloaddition... 

Keywords a-oxoamide, inclusion crystal, Norrish type II photoreaction, /1-lactam... 

Keywords (V-methyl cyclohex-1-enylanilide, inclusion crystal, [2+2]poto-cycloaddition, 3,4-dihydroquinolin-2( 177)-one... 

Keywords 4-isopropyltropolone methyl ester, inclusion crystal, [2+2]photo-cycloaddition, bicyclo[3.2.0]hepta-3,6-dien-2-one, methyl-4-oxocyclopent-2-ene-... 

Keywords anhydrous hydrazine, hydroquinone, dimethyl terephthalate, inclusion crystal, terephthalic acid dihydrazide... 

In this chapter, enantioselective photoreactions of achiral molecules in their own chiral crystals and in inclusion crystals with a chiral host compound that have been carried out mainly in our research groups are described. 

Even for the oxoamides which do not form chiral crystals, enantioselective photoconversion to optically active (3-lactams can easily be accomplished by photoirradiation in their inclusion crystals with an optically active host compound. For example, irradiation of a 1 1 inclusion complex crystal of 9 with 11 [8] gave (-)-10 of 100% ee in a quantitative yield [9], The host compound 11 is recovered and can be used again. The chiral arrangement of 9 molecules in the inclusion complex was studied by x-ray analysis [9], A schematic stereoview of the inclu-... 

Intramolecular [2 + 2] photocyclization reactions of 2- /V-(2-propcnyl)amino]cy-clohex-2-enones (67) are also controlled enantioselectively by carrying out irradiation in inclusion complex with a chiral host compound. When inclusion crystals of 67 with 12 are irradiated in the solid state, optically active 9-azatricyclo[5.2.1.0]-decan-2-ones (68) were obtained in the chemical and optical yields indicated in Table 3 [30],... 

Photoirradiation of inclusion crystals of 3-oxo-2-cyclohexanecarboxamide derivatives (69b-69d) with the optically active host compound 12b as a water suspension for 4 hr gave optically almost pure 2-aza-l, 5-dioxaspiro[3,5]nonane derivatives (70b-70d) [38], Optically pure 70b and 70c were prepared by the... 

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