Dimethylphenylsilyl propenes

Hiyama and coworkers produced the same allylation compounds via the in situ reaction of l,l-difluoro-3-(dimethylphenylsilyl)propene and aldehydes with catalytic tris(diethyl-aminojsulfonium difluorotrimethylsilicate (TASF) or potassium f-butoxide (equation 85)78-79. 

The isomeric 3,3-difluoro-3-(dimethylphenylsilyl)propene gave exclusively the same product (equation 86)79. 

Phenylacetylene 13 readily reacts with Me2PhSiH under CO pressure to give 3-dimethylphenylsilyl-2-phenyl-propenal 14a in the presence of a catalytic amount of Rh4(CO)i2 (Equation (2)). When 10-20 atm of CO pressure and 0.1-0.2 mol% of Rh4(GO)i2 are applied, the reaction is completed within 2 h at 100 °G. Silylformylation proceeds smoothly even at room temperature, though the reaction becomes slower (600-700 turnover frequency at room temperature after 17 h). The reaction does proceed in the absence of Et3N, but its presence improves yield and (Z)-selectivity of product 14a. ... 

Several procedures deal with optically active auxiliaries employed in stoichiometric amounts or more, but which are not covalently bonded to one of the reagents. These catalysts influence Simmons-Smith type cyclopropanations of allylic alcohols with moderate to excellent enantiose-lectivities. Whereas the reaction of ( )-3-phenyl-2-propen-l-ol (1) with diethylzinc and diiodo-methane in the presence of (17 ,25 )-A,-methylephedrine (2 equivalents) gives an enantiomeric excess of only 24% under optimized conditions107, the same reaction with (/ ,/f)-diethyl tartrate (1.1 equivalents) as ligand affords (1 ) ,27t)-fra i-l-hydroxymethyl-2-phenylcyclopropane (2) with up to 79% ee108, Similar results are achieved with the corresponding (Z)-olefin, and even higher enantioselectivities are obtained for dimethylphenylsilyl-substituted allylic alcohols such as 3109. 

Silylformylation of IV-propargyl tosylamides gives normal /S-silyl enal products, whereas the same reaction in the presence of l,8-diazabicyclo[5.4.0]undec-7-ene or triethylamine affords a-(dimethylphenylsilyl)methylene /3-lactams (eq 9). Propar-gylamines are transformed to 2-(dimethylphenylsilyl)methyl-2-propenals (eq 10). ... 

Alternate Names l,l -(l-propene-l,3-diyl)bis[l,l,l-trimethy-Isilane] (lE)-l-propene-l,3-diylbis[trimethylsilane] (E)-prop- 1-ene-1,3-diylbis(trimethylsilane) (IZ)- 1-propene-1,3-diylbis[trimethylsilane], CAS 141291-16-9 Bis(r-butyl-dimethylsilyl) derivative (l )-l-propene-l,3-diylbis[(l,l-dimethylethyl)dimethylsilane] Bis(dimethylphenyl) derivative [[(l )-3-dimethylphenylsilyl)-1-propen-l-yl]dimethyl-silyl]-benzene other derivatives are known but less widely used. 

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