Stannane compound with

Trialkyl(2-borylvinyl)stannanes react with sulphur bis(trimethylsilylimide) to yield heterocyclic ylide compounds, as shown in reaction 21277. 

Nucleophilic allysilanes or -stannanes react with aldehydes in the presence of Lewis acids (294). As illustrated in Scheme 122, the use of a chiral boron compound as catalyst affords the corresponding homoal-lylic alcohols of high enantiomeric purity (295). 

Non-aromatic organolithium compounds can be prepared by transmetallation of resin-bound stannanes [25] or by deprotonation of alkynes [26], triphenylmethane [27], or other resin-bound C II acidic compounds with lithium amides or similar bases (Figure 4.3). The reaction of polystyrene-bound trialkylboranes with diethylzinc yields resin-bound alkylzinc derivatives [28]. 

The second is the non-heterosubstituted lithiated anilide 297. This compound presents a remarkable example because it is configurationally unstable in the presence of TMEDA, but configurationally stable in the presence of (-)-sparteine or its achiral analogue di-n-butylbispidine 299.138 Treatment of the enantiomerically enriched stannane 296 with s-BuLi returns, after 1 h, racemic material in the presence of no diamine additive, or in the presence of TMEDA, indicating a configurationally unstable intermediate on this timescale. However,... 

In a study of synthetic routes to the phorbol class of compounds, Lautens cyclised the stannane 307 (with 5 equiv MeLi, to avoid stannane reincorporation) to the 7,5-fused ring system 3 0 8.138 This reaction also works in the synthesis of analogous saturated five-membered nitrogen and sulfur heterocycles (see below). 

The P —Te and As —Te bonds were not attacked by water5,6 or methanol5. Trimethyl-stannane similarly cleaved the group V element-tellurium bonds in these compounds5 and in their coordination compounds with chromium and molybdenum carbonyls7. 

When diethyl tellurium was heated with triorgano silanes, germanes, or stannanes, one or both tellurium-carbon bonds were cleaved and compounds with tellurium-group IV element bonds were formed3 4. 

Alkenyllithium compounds can also be prepared by metaUation of alkenes, particularly when alkenyl hydrogens are rendered acidic by an a-substituent (equation 22). Transmetallation of alkenyl stannanes with organohthium reagents gives alkenyUithium compounds with retention of alkene stereochemistry (equation 23). Tin lithium fransmet-allation has been used to prepare 1,4-dihthio-l,3-butadiene. Monosubstituted alkenylhthium compounds RHC=CHLi, can also be prepared from the corresponding diorganotel-luride, RHC=CHTeBu, by reaction with butylhthium in... 

SYNS BROMOTRIETHYLSTANNANE compounded with 2-PIPECOLINE (1 1) O STANNANE, BROMOTRIETmT.-, compounded with 2-PIPECOONE (1 1)... 

The state of the art of reductions with metal hydrides a decade ago was the subject of comprehensive reviews. A detailed survey of reductions of carbonyl compounds with alkali and alkaline earth metal hydrides, borane and derivatives, alane and derivatives, metal borohydrides, metal aluminohydrides, silanes, stannanes and transition metal hydrides was compiled. The properties, preparation and applications of each reagent were discussed together with methods for their determination, handling techniques... 

The radical anions of carbonyl groups can also be generated via PET from activated alkenes, e.g. allylic silanes or stannanes. Triplet excited aromatic ketones, a-dicarbonyls and Michael systems are suitable substrates for oxidizing allylic Group 14 organometallic compounds with subsequent formation of homoallylic alcohols or S-allylated ketones (Scheme 32) [120-122]. 

Silane, germane, and stannane can be synthesized by the reduction of a variety of silicon, germanium, or tin compounds with active metal hydrides. The general method described below, involving the lithium hydroaluminate (LiAlHi) reduction of silicon tetrachloride and tin (IV) chloride, is convenient for the eflficient preparation of 1-50 mmoles of silane and stannane. The method is easily adapted to the synthesis of the deuterio compounds, i.e., silane-d4, germane-dt, and stannane-d4, by... 

Organometallic compounds with a 3-butenyl moiety can produce cyclopropylmethyl derivatives via an addition of electrophiles to the terminal carbon atom of the double bond followed by the loss of the metallic group. 3-Butenylsilanes, -stannanes (equation 30 31,134 and -cobaltare the representative compounds. Thus, the reaction of... 

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