Organostannanes reactions with

T. Forngren, Y. Andersson, B. Lamm, B. Langstrom, Synthesis of [4-F-18]-1-bromo-4-fluorobenzene and its use in palladium-promoted cross-coupling reactions with organostannanes, Acta Chem. Scand. 52 (1998) 475-479. 

Reactions with Organostannane Reagents The Migita-Kosugi-Stille Reaction... 

It was also discovered that aryl and vinyl iodides, bromides, and triflates participated efficiently in cross-coupling reactions with organostannanes when catalyzed by palladlum-on-carbon in the presence of Cu(l) as cocatalyst.1... 

Ionomers have been synthesized from reaction of tin II and tin IV metal halides and organostannane halides through reaction with an ethylene-acrylic acid copolymer. Mass spectral, infrared spectral, and elemental analysis results are consistent with the formation of tin-containing ionomers. The products all exhibit "ionomer-like" properties and soften below 150 C, many softening below 50 C. 

Since the use of stoichiometric amounts of organostannane is unfavorable for the environment, they have established reaction conditions for a process that is catalytic in organostannane. Thus, the reaction with an alkenyl trichloroacetate as the precursor of the tin enolate in the presence of the catalytic amount of Me3SnOMe and the appropriate aldehydes afforded the corresponding aldol adducts with high enantio-and diastereoselectivities (Table 9.8).17 However, when the aliphatic aldehydes were used as substrates, the reaction did not take place at all. The proposed catalytic cycle is shown in Figure 9.3. It was also demonstrated that this catalytic system could be applied using a [3-lactone compound as an alkenyl trichloroacetate equivalent to... 

The mechanism of the Stille reaction involves an oxidative addition of the palladium(O) species into the carbon-halogen bond, a trans-metallation reaction with the organostannane and a final reductive elimination step releasing the product and thereby regenerating the palla-dium(O) catalyst. 

Carbamoyl chlorides. A direct preparation of carbamoyl chlorides from tertiary benzylamines (debenzylation) is by reaction with triphosgene. A-Methoxy-N-methyl-carbamoyl chloride, which is useful for coupling with various unsaturated organostannanes, is obtained from chloroformylation of the methoxylamine in the presence of pyridine. ... 

Regarding nonsilicon precursors, C-Sn bonds are stable enough toward hydrolysis. Numerous precursors such as R SnXs (X = Cl, -OR) and trichloro organostannanes are available. The trichloroorganotin precursors can also be transformed into trialkynylor-ganotins by reaction with alkynyllithium. 

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). 

Diethylamino-4-(4-methoxyphenyl)isothiazole-1,1-dioxide (17 Ar = 4-MeOPh) on treatment with one equivalent of bromine gave the dibromo derivative (18) which upon heating or by reaction with triethylamine furnished the mono bromo compound (19) on elimination of HBr. Palladium catalysed coupling of (19) with a variety of organostannanes provided good yields of 5-substituted isothiazoles (20) <97T15859>. 

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