Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest. Please login or sign up for a free trial to access the full content.
4.4.34.6.3 Variation 3: Reaction of Carbonyl Compounds with Dimetal Species Derived from (Dibromomethyl)(trimethyl)silane

DOI: 10.1055/sos-SD-004-00770

Oshima, K.Science of Synthesis, (20024727.

Several gem-dimetal compounds, such as dimagnesium and dizinc, have been prepared from (dibromomethyl)trimethylsilane upon treatment with magnesium or a zinccopper couple,[‌34‌] respectively. A more facile preparative method for [bis(bromozincio)methyl]trimethylsilane or dichromium species has been developed. Thus, treatment of (dibromomethyl)trimethylsilane (61) with chromium(II) chloride in dimethylformamide gives the gem-dichromium reagent. The addition of aldehydes to this dimetal species provides E-alkenylsilanes exclusively (Scheme 21).[‌35‌] However, a one-pot transformation of aldehydes to E-alkenylsilanes using triiodomethane, manganese metal, chlorotrimethylsilane, and a catalytic amount of chromium(II) chloride has been reported.[‌36‌] Esters (e.g., 64) are converted into β-alkoxy-substituted alkenylsilanes such as 65 by means of the reagent prepared from (dibromomethyl)trimethylsilane, zinc, titanium(IV) chloride and N,N,N,N-tetramethylethylenediamine.[‌37‌] Titanium(II) chloride mediated reaction of [bis(bromozincio)methyl]trimethylsilane with aldehydes also provides the corresponding alkenylsilanes, but with lower stereoselectivity.[‌38‌] The synthesis of 1,1-disilyl-substituted alkenes (e.g., 67) from aldehydes and dibromobis(trimethylsilyl)methane (66) using chromium(II) chloride in dimethylformamide has been reported.[‌39‌]

Meeeee 88 Meeeeeee ee Meeeeeee eeeeeeeee eeee Meeeeee Meeeeee Meeeeee eeee (Meeeeeeeeeeee)eeeeeeeeeeeeeee[‌88‌‌88‌]

Meeeeeeeeeee Meeeeeeeee

Meeeeeeee[(8M)-8-eeeeeeeee-8-eeee]eeeeee (88):[‌88‌]

Meeee eeeee, MMMMe (8.8eM, 88eeee) eee eeeee ee 88°M ee e eeeeeeeeee ee MeMe8 (88ee, 8.88eeee), eee Me (8.88e, 88eeee) ee MMM (88eM). Meeee eeeeeeee eee eeeeeee ee 88°M eee 88eee, e eeee ee MMM8 (8.8e, 8.8eeee) ee MMM (8eM) eee eeeee ee 88°M eeee 8eee, eee eee eeeeeee eee eeeeeee eee 8eee. M eeee ee 8-eeeeeeeeeeeeee (88; 8.88e, 8.8eeee) ee MMM (8eM) eee eeeee ee 88°M eeee e eeeeee ee 8eee eee eee eeeeeeeee eeeeeee eee eeeeeee ee 88°M eee 88e. Mee eeeee ee eee eeeeeee eeeeeeeee eeeeee eeee eeee eee ee eeeee eeeee eeeeeeee. Mee eeeeeee eee eeeeee eeee M8M (88eM) eee eeeeeeeee eeee eeeeeee (8×88eM). Mee eeeeeee eeeeeeee eeee eeeeee eeee ee Me8M8M8 eee eeeee, eeeee (MeMM8), eee eeeeeeeeeeee. Meeeee eeeeeeeeeeeeee (eeeeee eee, eeeeeee) eeee, eeeee eeee 8-eeeeeeeee-8-eee (88ee, 88%), 88 ee e eeeeeeeee eee; eeeee: 8.8e (88%); eeeee (M/M) >88:<8.

(8-Meeeeeeeeeeee-8-eeee)eeeeeeeeeeeeeee (88):[‌88‌]

M eeee ee MeMe8 (8.8M, 8.8eeee) ee MM8Me8 eee eeeee ee 8°M ee e eeeee eeeeeee ee MMM (8.8eM) eee MM8Me8 (8eM) eeeee eeeee. Me eee eeeeee eeee ee 88°M eee eeeee MMMMM (8.8eM, 88eeee) eee eee eeeeeee eee eeeeeee ee 88°M eee 88eee. Me eeee (8.88e, 88eeee) eee eeeee eee eee eeeeeeeee eeeeeee eee eeeeeee ee 88°M eee 88eee. Mee eeeee ee eee eeeeeeeeee eeeeee eeee eeeeeeee eeeeee ee eeee eeeeeeee eeee ee e eeeeeeee eeeeeeeeee eeeeeee. M eeee ee eeeeee eeeeeee (88; 888ee, 8.8eeee) eee MMMMMMe8 (88; 8.88e, 8.8eeee) ee MM8Me8 (8eM) eee eeeee, eee eee eeeee eeeeeeeee eeeeee eeee eeeeeee eeeee. Meeee eeeee eeeeeee ee 88°M eee 8e, MMM (88eM) eee eeeee eee eee eeeee eee eeeeee ee 8°M eeeeeeee ee eeeeeeee ee eee. ee M8MM8 (8.8eM). Meeee ee eee eeeeeee ee 8°M eee eeeeeee 8e, eee eeeeeee eee eeeeeee eeee Me8M/Me8M (888:8, 88eM) eee eeee eeeeee eeeeeee eeeeeee e eeeee eeeeee ee eeeee eeeeeee (eeeeeeee MMM). Mee eeeeeeeee eeee eee eeeeeeeeeeee eee eee eeeeeeeeeeeee eeeee eeeee eee eeeeeee ee eeeeeeeeee (Meeee Meeee-Mee, eeeeeee/Me8M 888: 8, 88eM). Mee eeeeeeee eee eeeeeeeeeeee eeeee eee eee eeeee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee [eeeee eeeeeee (eeeeeeee MMM), eeeeeee/Me8M 888: 8] ee eeee 88; eeeee: 888ee (88%).

8,8-Mee(eeeeeeeeeeeeee)eee-8-eee (88):[‌88‌]

M eeee ee eeeeeee (888ee, 8.8eeee) eee (MMM)8MMe8 (88; 888ee, 8.8eeee) ee eee, eeeeeeeeeeee MMM (8eM) eee eeeee eeeeeeee ee e eeee-eeeeeee eeee ee MeMe8 (88% eeee, 8.88e, 8.88eeee) ee eee, eeeeeeeeeeee MMM (8eM) eeeee eeeee ee 88°M. Meeee 88e ee 88°M, M8M (88eM) eee eeeee eee eee eeeeeee eee eeeeeeeee eeee Me8M (8×88eM). Mee eeeeeeee eeeeeee eeeeeeee eeee eeeeee eeeeeeeeeeee eeee ee 8M MeMM8 (88eM), M8M (88eM), eee eeeee (88eM), eeeee (MeMM8), eee eeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeeeeeeeee ee eee eeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeeee) eeee 88 ee e eeeeeeeee eee; eeeee: 888ee (88%).

References