Organostannanes acid chlorides

Ketones can be obtained by coupling of acid chlorides with organostannanes or by carbonylative couplings. The first reaction is one of the older and more general Stille coupling reactionsi i 122 and continues to be used under essentially the original conditions.1 3... 

Ketones are formed from pyridylzinc halides on acylation with acid chlorides or anhydrides in reactions with benzoyl chloride or benzoic anhydride, pyridyl ketones (307) are formed in moderate yields. Reactions with 3-iodoquinoline gave the 3-benzoyl derivative 308. Organostannanes may be a better choice for ketone formation (see above). 

A report in 2005 by Black and Arndtsen [106a] who reported a copper-catalyzed multicomponent method that leads to a-substituted amides using acid chlorides with organostannanes (Figure 1.29). 

Procedures for synthesis of ketones based on coupling of organostannanes with acid chlorides have also been developed. The catalytic cycle is similar to that involved in the coupling with organic halides. The scope of the tin compounds to which the procedure can be applied is wide and includes successful results with tetra-n-butyltin. This implies that the reductive elimination step (step c) in the mechanism occurs faster than p elimination of the butylpalladium intermediate. 

The first report by Stille was published in 1978 and dealt with the formation of ketones, mediated by a palladium(II) catalyst, starting from acid chlorides and organostannanes. For instance acetophenone was produced in 89% isolated yield upon treatement of a solution of benzoyl chloride and tetramethylstannane in HMPA at 65 °C for 10-15 minutes in presence of benzylchlorobis(triphenylphosphine)palladium(II) (8). The experimental conditions reported in this article proved to be milder and higher yielding than the ones reported by Kosugi, Shimizu and Migita (see below). 

The original report by Stille was between an acid chloride and an organostannane sec section 1.1.6.2. 

We note that while tin reagents have often been employed for the organoboron halides/ the use of organostannanes as starting materials can also be applied to the synthesis of heavier group 13 derivatives. In the context of polyfunc-tional Lewis acid chemistry, this type of reaction has been employed for the preparation of ort/ o-phenylene aluminum derivatives. Thus, the reaction of 1,2-bis(trimethylstannyl)benzene 7 with dimethylaluminum chloride, methylaluminum dichloride or aluminum trichloride affords l,2-bis(dimethylaluminum)phenylene 37, l,2-bis(chloro(methyl)aluminum)phenylene 38 and 1,2-bis(dichloroalumi-num)phenylene 39, respectively (Scheme 16). Unfortunately, these compounds could not be crystallized and their identities have been inferred from NMR data only. In the case of 39, the aluminum derivative could not be separated from trimethyltin chloride with which it reportedly forms a polymeric ion pair consisting of trimethylstannyl cations and bis(trichloroaluminate) anions 40. 

Cellulose can be modified with organostannane chlorides, such as dibutyl or triphenyl derivatives [91,92], or with organotin halides in the presence of bisethylenediamine copper(II) hydroxide [93]. Epoxy-activated cellulose was prepared by reacting cellulose acetate fibers with sodium methoxide, followed by reacting it with epichlorohydrin in DMSO. This epoxy-activated cellulose has proved to be a useful intermediate to react with substances containing active hydrogen, such as amine, amino acid, or carboxylic acids [94], as shown in Fig. 3. Epoxidized cellulose has also been converted to a thiol derivative via reduction of a thiosulfate intermediate [95], and sulfoethylcellu-[ose has been obtained from sodium chloroethanesulfonate [96]. Cellulose... 

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