Science of Synthesis

Delvos, L. B.; Oestreich, M., Science of Synthesis Knowledge Updates, (2017) 1, 91.

[Dimethyl(phenyl)silyl]pinacolborane (‌66‌, R2 = Me) and (methyldiphenylsilyl)pinacolbo­rane (‌66‌, R2 = Ph) react with terminal alkenes ‌65‌ in the presence of a platinum catalyst, furnishing 1,2-difunctionalized alkanes ‌67‌ in a regioselective manner (‌Scheme 33‌).[‌64‌] In contrast to alkyne silaboration, palladium complexes are completely ineffective, and the minor byproduct is not the 1,2- but the 1,1-difunctionalized regioisomer ‌68‌ (see Section ‌4.4.7.2.1.1‌). Even though the reaction scope was studied in depth with silylboronic ester ‌66‌ (R2 = Me), it is important to note that bulkier derivative ‌66‌ (R2 = Ph) gives better results for the silaboration of oct-1-ene. Alkyl substituents bring about regioselectivity issues, whereas aryl-substituted alkenes transform exclusively into ‌67‌.

‌Meeeee 88‌ Meeeeeeeeeeeee Meeeeeeee ee 8,8-Meeeeeeeeeeeeeee Meeeeee ee Meeeeeee-Meeeeeeee Meeeeeeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

Mee eeeeeeeee ee 8,8-eeeeeeeeeeeeeeee eeeeeee ee eeeeeeeeee eeeeeeeeee ee ee eeeeeeeeeeeeee eeeeeee ee eeee eeeeeeeeeeeeee.[‌88‌] Meeeeeee eeee eeeeeeeeeee eeeee eeeeee ‌88‌, eeeee-eeeeeeeeeee eeee-eeeeeeee eeeee eeeeee eeeee-‌88‌ eee eeeeeeee ee eee eeeeeeeeeee eeeeeeeeeeee (‌Meeeee 88‌). Me eeeeeeeee eeeeeeee eeeeeee eee eeeeeeeeeeeeeeeeeeeeeeeeeee ee eeeeee eee eeeeeeeee ee eeeee eeee eeeeee eee eeeee/eee eeeeeeeeeeeee ee ≤88:8 eee e eeeee ee eeeeeeeee eeeeeeeeee. Meeeeeeeeeeee, eee eeeeeeeeeeeeeeeeeeee ee eee eeeeeeee eeeeeee eeee eeeee eeeeeeeee eeeeee ‌88‌, eeeeeeeee ee eee-eeeeeee eee-‌88‌ eeee eeeeeeee eeeeee eeeeee eee eeeeeeeeeeeeeeeeeee.

‌Meeeee 88‌ Meeeeeeeeeeeeeeeee Meeeeeeeeeeeee Meeeeeeeeeee ee Meeeeeee Meeeeee[‌88‌]

‌Meeeeeeeeee 88‌

e Meeeeeee eeeee ee eeee eeeeeeeeeeeee.

e Meeeeeee eeee 88% eeeeee.

Me eee eeeeeeeeeeee eeeeeee ee eee eeeeee eeee ee eeeeeee ee 8,8-eeeeeeeeeeeee eeeeeee eeee ee ‌88‌ eee ‌88‌, e eeeeeeeeeeeeeee eeeeeeeeee eeeee M-eeeeeeeeee eeeeeee eeeeeeeee ‌88‌ eee ‌88‌ eeeeeee e eeeeeeeeee eeeee (‌Meeeee 88‌).[‌88‌] Mee eeeeeeee eeeeeeeeee eeeeeee eeee eeeeee eeee eee eeeeeeeeee eeeeee eeee ee eee eeeeeeee eeeeee eeeeee eeee eeee eeeee ee β-eeeeeee eeeeeeeeeee ee eee Me—Me—M eeeeeeeeeeee eeeee eeeeeee eeeeeeeeeeeeeee. Mee eeeeeeee ee eeeeeee eee e eeeee ee eeeee eeeeeeeeeeee eee M8 eee M8. Meee M8 ee ee eeeee eeeee eeeeeee eeeeeee ee e eeeeeeeeeeeee eeeeeee eeeeeeee eee eeeeeeee (eee eeeee), eeeee eeeeeeeee eeeeeeee eeee eeeeeeee ee eeeeeeeeeeee eeee e eeeeee ee e eeeeee eeeee.

‌Meeeee 88‌ Meeeeeeeeeeeee Meeeeeeeeeeeeee Meeeeeee ee 8,8-Meeeeeeeeeeee Meeeeee[‌88‌]

‌Meeeeeeeeee 88‌

e MMM eeeee.

Meeeeeeeeeee Meeeeeeee

8-{8-[Meeeeeee(eeeeee)eeeee]eeeee}-8,8,8,8-eeeeeeeeeee-8,8,8-eeeeeeeeeeeeee ‌88‌ (M8 = Me); Meeeeee Meeeeeeee:[‌88‌]

Me e eeee ee Me(η8-M8M8)(MMe8)8 (88 ee, 88 µeee, 8.8 eee%) ee 8,8-eeeeeee (8 eM) eeee eeeee 8-[eeeeeeee(eeeeee)eeeee]-8,8,8,8-eeeeeeeeeee-8,8,8-eeeeeeeeeeeee (‌88‌, M8 = Me; 8.8 e, 8.8 eeee, 8.8 eeeee) eee eee eeeeeeeeeeeee eeeeee ‌88‌ (8.8 eeee, 8.8 eeeee). Mee eeeeeee eee eeeeee ee eeeeee eee 8 e, eeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee).

8,8-Meeeeeee-8-[(8,8,8,8-eeeeeeeeeee-8,8,8-eeeeeeeeeeee-8-ee)eeeeee]-8,8-eeeeeeeeeeee eeeee-‌88‌; Meeeeee Meeeeeeee:[‌88‌]

M eeeeeee (8.8 eM) eeee ee Me(eee)8 (8.8 ee, 88 µeee, 8.8 eee%), MeMe8M (8.8 ee, 88 µeee, 88 eee%), eee eee eeeeeeeeeeeee eeeeee ‌88‌ (8.88 eeee, 8.8 eeeee) eee eeeeee ee 888 °M. Mee eeeeeeee eee eeeeeeeee ee MMM. Meeee eeeeeeeeeee ee eee eeeeeeeee, eee eeeeeeeee eeee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeee/eee eeeee ee eee eeeee eeeeeeeee eee eeeeeeeeee ee 8M MMM eeeeeeeeeeeee eeeeeeee. Mee eeeee eeeeeeee eee eeeeeeee ee eeee-ee-eeee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Me eeee eeeeeeeee, eeeee eeeeeee ee eeeeeeeee-eeeeeeeee eeee eeeeeeee eeee eeeeee eeeee eeee eee eeeeeee eeeeeeeeeeeee, eeeee eeeee eee ee eeeeeeeee ee eeeeeeeeeeee. Me eeee eeeee, eeeeeeeeeeee eee eeeeeeeee eeeee MMMM.

Meeeeee Meeeeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

M eeeee eeee eeeeee e Meeee MMMM eeeeeeee eee eeeeeee eeee Me8M (88 µeee, 88 eee%), Me(eee)8 (8.8 ee, 88 µeee, 8.8 eee%), eeeeeee (8.8 eM), eee ee eeeeee ‌88‌ (8.88 eeee, 8.8 eeeee). Mee eeee eee eeeeee ee eee eeeeeeee, eee eee eeeeeee eeeeeee eee eeeeee ee 888 °M. Mee eeeeeeee eee eeeeeeeee ee MMM. Meeee eee eeeeeeee eee eeeeeeee (8–88 e), eee eeeeeeeee eeee eeeeeeeeee. Mee eeeee eeeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee) ee MMMM.

Meeeeee Meeeeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

M eeeee eeee eeeeee e Meeee MMMM eeeeeeee eee eeeeeee eeee (8-M8MM8M8)8M (88 µeee, 88 eee%), Me(eee)8 (8.8 ee, 88 µeee, 8.8 eee%), eeeeeee (8.8 eM), eee ee eeeeee ‌88‌ (8.88 eeee, 8.8 eeeee). Mee eeee eee eeeeee ee eee eeeeeeee, eee eee eeeeeee eeeeeee eee eeeeee ee 88 °M. Mee eeeeeeee eee eeeeeeeee ee MMM. Meeee eee eeeeeeee eee eeeeeeee (8–88 e), eee eeeeeeeee eeee eeeeeeeeee. Mee eeeee eeeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee) ee MMMM.

References