Ethers organotin compounds

Phenolic compounds are used in commercial or consumer products or building materials (Rudel et al., 2001), especially ethoxylated alkylphenols of octylphenol and nonylphenol, which are widely used in surfactants (Ying, Williams and Kookana, 2002). They are known as endocrine disrupting compounds (EDC) as they bear hormonally active properties. Other EDCs found indoors include phthal-ates (Section 11.2.7), certain pesticides, organotin compounds (Section 11.2.5) and polybrominated diphenyl ethers (Section 11.2.8) (Rudel et al., 2001, 2003). 

The stemona alkaloid stemonamide (49) was synthesized starting from a-stannyl acetate 47 and 2-stannyl pyrrolidine 48. The oxidative coupling of stannyl acetate 47 with acetylenic silyl enol ether affords the functionalized C-7 unit which corresponds to the side arm of the pyrrolidine ring. Then, introduction of the C-7 unit to the pyrrolidine ring is performed by the oxidative generation of acyliminium ion. The carbon skeleton of stemonamide was thus constructed efficiently as shown in Scheme 19 by employing organotin compounds. ... 

When the ligand system consists of chlorine atoms, monoalkyl- and monoaryl-titanium(IV) compounds are readily made from TiCU by a chlorine atom replacement. The parent compound in this series, MeTiCb, is made conveniently from the reaction of TiCU and dimethylzinc without the use of ethereal solvents, the preparation being carried out in n-pentane or dichloromethane. Other methylating species can be used, such as MeMgBr, MeLi and MeAlCh. When MeLi is used in diethyl ether, an equilibrium takes place between different complexation states of Ti in the resulting MeTiCU with the solvent (equation 8). Transmetallation from organotin compounds like (15 equation 9) has also been utilized to make trichlorotitanium compounds. ... 

A-(Morpholin-4-yl)-l-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-l//-pyra-zole-3-carboxamide (61). To a magnetically stirred solution of organotin compound 66 (290 mg, 0.40 mmol) in carbon tetrachloride (15 mL) was added dropwise a 0.02 M solution of iodine in carbon tetrachloride (25 mL, 0.50 mmol) at room temperature. After TLC showed that the reaction was completed, carbon tetrachloride was removed under reduced pressure. The residue was purified by flash column chromatography on silica gel (petroleum ether ethyl acetate 50 50) to afford the desired product 61 as a white solid (215 mg, 97% yield) MP 265-268°C (dec.). 

---