In recent years, fluorous chemistry has emerged as one of the promising fields of green chemistry. The term “fluorous” is a coined word meaning having affinity with fluorocarbons. Highly fluorinated compounds, in another words fluorous compounds, are insoluble in general organic solvents or water. However they are highly soluble with fluorous solvents such as perfluoroalkane. Fluorous chemistry is the technique of making use of this property, and it is applied to many organic reactions. Although fluorous solvents are generally immiscible with common organic solvents and water, certain fluorous solvents are able to form homogeneous solutions with some organic solvents at elevated temperatures. The characteristic features of these fluorous solvents is that they have boiling points properties that are almost equal to those of the corresponding hydrocarbons, regardless of their molecular weight, and these solvents have a high solubility of many gases and incombustible property. Taking the advantage of these properties, Horváth et al. accomplished the hydroformylation of olefins using a fluorous rhodium catalyst in perfluoromethylcyclohexane and toluene in 1994.¹⁾ This was regarded as the origin of the fluorous chemistry. This reaction uses perfluoromethylcyclohexane and toluene as solvents, which exist as a biphasic system at room temperature. In this system the fluorous catalyst exists in the fluorous phase and the olefins in the organic phase. However, the two phases form a homogeneous solution when heated. The reaction then proceeds by introduction of carbon monoxide and hydrogen gases. When the reaction is complete and the system is cooled, the two phases reappears, where the resulting product is found in the organic phase and the fluorous catalyst is in the fluorous phase; thus, the catalyst and the product are easily separated. The biphasic system using a fluorous solvent and an organic solvent is called Fluorous Biphase System (FBS), and the multiple phase system is called Fluorous Multiphase System (FMS). The advantages of FBS and FMS are that the resulting product and the catalyst can be easily separated simply by separating the fluorous phase from the other phase after the reaction. After separation, the fluorous phase containing the fluorous catalyst can be reused.

Curran et al. have introduced the use of fluorous substituents (fluorous tags) into non-fluorous substrates for the synthesis of isoxazoline.²⁾ After the reaction, the fluorous product was separated by fractional extraction with dichloromethane, water, and perfluorohexane. Following this report, numerous applications of fluorous chemistry have been made in combinatorial chemistry³⁾ and oligosaccharide syntheses⁴⁾.

Fluorous Solvents

Fluorous Compounds

Fluorous Solvents

D2669	H0946	H0085
P0837	O0292	P0856
P1420	T1012	P0839

Fluorous Compounds

Fluorous Alkanes, Fluorous Alkenes

P1102	H0846	T2496
U0076	N0601

Fluorous Alcohols

H1233	E0239	H0845
N0600	T2528	D1101
H1035	H1232	N0814
N0810	P0904	T1701
P0845	H0548	D2891
O0294	O0114	H0746
H0649	H1279

Fluorous Carboxylic Acids, Anhydrides and Halides

H0743	B1698	P1449
D2465	H0843	H0024
H0337	H0508	H0892
H0658	N0607	N0605
N0809	O0260	P0764
T2492	T1545	U0067
U0075

Fluorous Esters

H0744	D3589	D3590
H1038	H0594	N0689
M1915	H1033	M2022
M1916	M1912	P1453
M1917	M1914	M1913

Fluorohalides

D3573	D3572	D2804
H1084	T2074	T2482
D2333	H0844	H0946
P1084	H0689	H0596
N0808	N0499	D2329
P1753	T2479	T1098
U0081

Fluorous Sulfonic Acids & their derivatives

H1281	H1176	H0781
H1055	N0710	N0709
N0677	P1098	H0729
N0711

Other Fluorous Compounds

P1081	P1080	H1056
E0462	B2340	H0467
A1330	O0318	M1433
N0872	P1754	U0083
T0859	T0829	T0828
P1106	T2037	P1363
H0926	H1057	P1452
U0071	N0645	P1162
P1163	H1058	N0712
T1770	T2720	P1134