Organotin amides

The ester 870 is prepared by the cross-coupling of the chloroformate 869 with an organotin reagent. Some chloroformates are easily decomposed by a Pd catalyst, and hence the reaction should be carried out by slow addition of the chloroformates. Similarly, the amide 872 is prepared by the reaction of the carbamoyl chloride 871 [742]. The coupling of alkylcopper with ethyl chloroformate catalyzed by Pd affords esters[743]. 

Schreiber and co-workers (436) prepared a library calculated to contain 2.18 million polycyclic compounds through the 1,3-dipolar cycloaddition of a number of nitrones with alkenes supported on TentaGel S NH2 resin (Scheme 1.83). (—)-Shikimic acid was converted into the polymer bound epoxycyclohexenol carboxylic acid 376 (or its enantiomer), coupled to the resin via a photolabile linker developed by Geysen and co-workers (437) to allow release of the products from the resin in the presence of live cells by ultraviolet (UV)-irradiation. A range of iodoaromatic nitrones (377) was then reacted with the ot,p-unsaturation of the polymer-bound amide in the presence of an organotin catalyst, using the tandem esterification/ dipolar cycloaddition methodology developed by Tamura et al. (84,85) Simultaneous cyclization by PyBrop-mediated condensation of the acid with the alcohol... 

SlLYL ENOL ETHERS Chiorotrimethylsilane-Zinc, 82 Lithium amides, chiral, 159 Lithium tri-sec-butylborohydride, 167 Organotin reagents, 211 Osmium tetroxide-Trimethylamine N-ox-ide-Pyridine, 223... 

The elimination of amines may also be accomplished by using the reactions of organotin amides and transition-metal hydrides, or transition-metal amides and tin hydrides4. Neither route has attracted much attention recently. 

In the same way, the coupling reaction of acyl chlorides and organotins is particularly efficient and general . This represents an alternative to the carbonylative three-component coupling reaction, and gives access to various aldehydes, ketones and a, fi-unsaturated ketones. A similar reaction is feasible with chloroformates, carbamoyl chlorides and snlphonyl chlorides, giving respectively a, -unsaturated esters, amides and sulphones . ... 

Tin-nitrogen bonded compounds are generally formed by reaction of an alkali or alkaline earth metal amide with an organotin halide compoundsofthe types R Sn(NR2)4- , ( = 1-3), (R3Sn) NR (n = 1-3), andcyc/o-(R2SnNR0 ( = 2 or 3) can be prepared (equation 79). Other routes include transaminations (equations 80 and 81). Tin carboxamides and snlfonamides have been obtained by reaction of tin oxides or hydroxides with amides (equation 82). 

These compounds are most readily obtained by hydrolysis of organotin hahdes, especially under basic conditions, although hydrolysis of alkoxides and amides, etc., can also be used. Hydrolysis of di- and trihalides occurs in a stepwise fashion and various of the partial hydrolysis products have been characterized (Scheme 19). 

S.8.5.4.1. by Reaction of an Organotin Amide with a Transition- or Inner Transltlon-Metal-Hydride Complex. 

The organotin-mediated cycUsations of2-(2-bromophenyl)-i f-alkenylacet-amides 112 were investigated by Taniguchi et al. [99] (Scheme 24). The cy-clisation mode depended on alkenyl substituent and, as expected, for... 

Louie, J., Hartwig, J. F. Transmetalation, Involving Organotin Aryl, Thiolate, and Amide Compounds. An Unusual Type of Dissociative Ligand Substitution Reaction. J. Am. Chem. Soc. 1995,117,11598-11599. 

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