Science of Synthesis

Miyaura, N., Science of Synthesis, (2005) 6, 273.

The addition of the B—H bond across a C—C multiple bond proceeds in a syn and anti-Markovnikov manner. Many functional groups can tolerate the hydroboration, so it is possible to synthesize reactive intermediates containing those functional groups and to directly utilize those intermediates for organic synthesis. The details of the scope, stoichiometry, regioselectivity, and stereoselectivity in the hydroboration of alkenes and alkynes have been reviewed extensively.[‌68‌–‌70‌] For the preparation of boronic acids the hydroboration of alkenes with boron dihalides (e.g., HBCl2, HBBr2•DMS, HBCl2•DMS) or catecholborane (‌49‌, 1,3,2-benzodioxaborole), followed by hydrolysis with water is a suitable method (‌Scheme 13‌). The boron dihalides (HBBr2•DMS and HBCl2•DMS) are easily available via the disproportionation between the corresponding boranes (BH3•DMS) and boron trihalides (BBr3•DMS or BCl3•DMS) in a ratio of 1:2.[‌73‌] Although hydroboration with a boron dichloride–dimethyl sulfide complex (HBCl2•DMS) requires the presence of a stoichiometric amount of a Lewis acid, such as boron trichloride,[‌74‌] a boron dibromide–dimethyl sulfide complex (HBBr2•DMS) directly adds to internal and terminal alkenes at 40°C giving alkyl(dibromo)borane–dimethyl sulfide complexes, e.g. ‌50‌, which can be easily hydrolyzed to alkylboronic acids, e.g. ‌51‌.[‌74‌–‌76‌] On the other hand, boron dichloride, generated in situ from boron trichloride and triethylsilane, is highly reactive and allows hydroboration of alkenes at −78°C.[‌77‌] The reaction of 1,3,2-benzodioxaborole (‌49‌) with terminal alkenes can be performed at 100°C.[‌78‌,‌79‌]

‌Meeeee 88‌ Meeeeeeeeeee Meeee eee Meeeeeeeeeeee ee Meeeeee[‌88‌]

Meeeeeeeeeeee ee eeeeeeeeee eeeeeeee eee eee eeeeeeeeeeeeeee eeeeeeeee ee eeeeeeeeeeee eeeee. Mee eeeeeeeeeeeee ee eeeeeeee eeeeeee eeee eeeeeeeeeeeeee (‌88‌) eeeee eeeee ee 88°M ee eee eeeeeee ee e eeeeeee eee eee eeee eeee eee eee eeeeeeeee ee eeeeeeeeeeee eeeee, eeee ee ‌88‌ (‌Meeeee 88‌).[‌88‌–‌88‌] Mee eeeeeeee eee ee eeee eeeeeee eee ee eeeeeeeeeeee, eeee ee eeeeeee, eee ee eeee eeee ee eeeeeeeeeeeeeee. Me eeee eeeeeeeee eeee eeeee eeeee ee eeeeeeeeeeee eeeee ee eeee eeeeee. Meeeeeeeeeeee ee eeeeeee eeee e eeeee eeeeeeeee–eeeeeeee eeeeeee eeeeeee (MMMe8•MMM) ee eeeeeeeeeeeeeee eeeeeeee ee eeeeeeeeee eeee eeeee ee e eeeeeeeeee eeeeeeeeeee.[‌88‌] (−)-Meeeeeeeeeeeeeeeeeeeeee (Mee8MM) ‌88‌ eee eeee eeee ee eeeeeee eeee eeee eeeeeeeeeeeeeeee eee eeeeeeee eeeeeeeeeee eee eeeeeee eeeeee ee eeeeeeee-eeeeeeeeeee eeeee.[‌88‌–‌88‌] Mee eeeeeee, eeeeeeeee ee eee eeeeeeeeeee eeeeeeeeeeee ‌88‌ eeee e eeeee eeeeee ee eeeeeeeeeeee eeeeeeeeeee eeeeeeeeee eee eeeeeeeeeeeeeee eeeeee, eee eeeee eeeeeeeeee eeeeeeeeeeee eeee ‌88‌ ee eeeeeeee. Meeee eeeeeee eeee eeee eeeeeeeeeeeeeee eeee eee eeeeeee eeeeeeeee ee eeeeeeeeee eeeeeeeee eeeeeeeee ee eee eeeeeeeeeeee ee eeeeee eeeeeeee eee eeeee eeeeeeeeee ee eeeeeeeeeeeeee eeeeeee.

‌Meeeee 88‌ Meeeeeeeeeee Meeee eee Meeeeeeeeeeee ee Meeeeee[‌88‌–‌88‌]

Meeeeeeeeeeee ee eeeeeeee eeeeeee eeeeeeeee ee e eeeeeee ee eeeeeeeeeeee ee eee eeeeeeee eee eee eeeeeeeeeee ee eeeeeeeeeeee. Meeeeeee eee eeeeeeee M- ee M-eeeeeeeeeeee eeeee eee ee eeeeee- eee eeeeeeeeeeeeeeee eeeeeeeeeee eeee M-(8-eeeeeeeee)eeeeeeeee ‌88‌, eeeee eee eeeeee eeeeeeeee eee eeeeeeeeeeeee ee 8-eeeeeee-8-eeee ‌88‌ (‌Meeeee 88‌). Mee eeeeeeee MM8-eeee eeeeeeeeeeee ee eee eeeeee eeee e eeeeeeeee eeeeee eeeeeeee ee eeeeeeeeee eeee eeeee eeeeeee M-eeeeeeeeeeee eeeee ‌88‌ eeee 88% eeeeeeeeeeee.[‌88‌,‌88‌] Mee eeeeeeee ee eeeeeeeee ‌88‌ eeee eeeee-, eeeee-, ee eeeeeeeeeeee eeee eeeee eeeee eeee eeeeeeee eeeeeeeee ee eeeeeeeeeeeee ee eee ee8 eeeeee, eeee eeeeeeeee M-eeeeeeeeeeee eeeee ‌88‌ eeeee eeeeeeeeee ee M-eeeeeeeeeeeeee ‌88‌.[‌88‌,‌88‌] Meeeeeeeeeeee, eee eeeeeeeee-eeeeeeeee eeeeeeeeee ee eee M—M eeee eeee eeeee-, eeeee-, ee eeeeeeee eeeeeeee ee eeeeeeee ee eeeeeee M-eeeeeeeeeeeeee eeee eeeeeeeee ee eeeeeeeeeeeee ee eee M—M eeee.[‌88‌]

‌Meeeee 88‌ Mee Meeeeeeee ee Meeeeeeeeeee Meeee ee Meeeeeeeeeeee ee 8-Meeeeee-8-eeee[‌88‌–‌88‌]

Meeeeeeeeeee Meeeeeeee

Meeeeeeeeeee Meee (‌88‌):[‌88‌]

M 888-eM eeeee eeeeee eeee e eeeeee eeeeeeeee eee eeeeeee eeee eee-8-eee (8.88 eM, 88 eeee) eee MM8Me8 (88.8 eM). M 8.8 M eeee ee MMMe8•MMM ee MM8Me8 (88 eM, 88 eeee) eee eeeeee eeeee eee eee eeeeeee eee eeee eeeeeeee eee 8 e. Mee eeeeeee eee eeeeeee ee eeeeeeeeeee ee eeeee eee eee eeeeeee eee eeeeeeeee (88–888°M/8 Meee) ee eeee eee eeeee(eeeeeee)eeeeee–eeeeeeee eeeeeee eeeeeee ‌88‌; eeeee: 88%. M 8 M eeee ee eee eeeeeee ‌88‌ ee MM8Me8 (88 eM, 88 eeee) eee eeeee ee e eeeeeee eeeeeee ee M8M (8 eM) eee Me8M (88 eM) ee 8°M eee eeeeeee. Meeee eeeee eeeeeee eee 88 eee, eee eeeeee eeee eeeeeeeee. Mee eeeeeee eeeee eee eeeeee eeee eeee M8M (8 × 88 eM) eee eeeee (88 eM), eeeee (MeMM8), eee eee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee; eeeee: 88%; ee 88°M.

[(8M)-8-Meeeeeeee-8-ee-8-ee]eeeeeee Meee (‌88‌); Meeeeee Meeeeeeee:[‌88‌]

Meeee eeeee, e Meeeeee–Meeeee eeeeee eee eeeeeee eeee eeeeeeeeeeeeee (‌88‌; 88 e, 8.8 eee) eee 8-eeeeeeeee-8-eee (88.8 eM, 8.8 eee) ee 8°M. Mee eeeeee eee eeeeee, eee eee eeeeeee eee eeeeeee eee 88 eee ee ee eee 8 e ee 88°M. Mee eeee eee eeeeee ee ee, eee ee eeeeeee eee eeee eeee M8M (888 eM) eee eeeeeee eee eeeeeeeeee. Mee eeee eee eeeeeee ee ee eee 8 e. Mee eeeeeee eee eeeeee ee ee eee eeee. Mee eeeeeeeee eeeee eeeee eee eeeeeeeee ee eeeeeeeeee eee eeeeeeeeee eeeeee eeee eee-eeee M8M ee eeeeee eeeeeeee, eee eeeee ee eee; eeeee: 8.8 e (88%); ee 88–88°M.

[(8M)-8-(Meeeeeeee)eee-8-ee-8-ee]eeeeeee Meee [‌88‌, M8 = (MM8)8MMe]; Meeeeee Meeeeeeee:[‌88‌]

Me e eeee ee MM8•MMM (8.8 eM, 88 eeee) ee MMM (88 eM) eee eeeee eeeeeeee α-eeeeee (88 e, 88 eeee) ee −8 ee 8°M. Mee eeeeeee eee eeeeeee eee 8 e ee 8°M eee 8 e ee ee, eee 8-(eeeeeeeee)eee-8-eee (8.88 e, 88.88 eeee) eee eeeee ee −88°M. Mee eeeee eeeeeeeeeee ee (Mee)8MM (‌88‌) eeeeeeeeeee eeeeeeeeee eeeeee eeeeeeee eee eeeeeee ee −88°M eee 8.8 e. Meeee eeeeeeee eee eeeeeee 8 e ee ee, MeMMM (88 eM) eee eeeee ee 8°M. Mee eeeeeee eee eeee eeeeeeee eeeeeeeee. Mee eeeeeeeee eeee eeee eeeeeee ee eeeee. Meeeeee (88 eM), eeeeeeee ee 8 M ee MeMM (88 eM), eee eeeee ee eee eeeeeee. Mee eeeeeee eee eeeeeee eeeeeeeeee eee 8 e eee eee eee eeeeee eeee eeee eeeeeeeee. Mee eeeeeee eeeee eee eeeeeeeee eeeeeee eeee ee MeMM (8 × 88 eM). Mee eeeeeeee eeeeeee eeeeee eeee eeeeeeeee eeee ee MMe ee 8°M ee eeeeeeeeeee eee eeeeeee eeee. Mee eeeeeee eee eeeeeeeee eeee Me8M, eeeee (MeMM8), eee eeeeeeeeeeee ee eeee e eeeee eeeee; eeeee: 8.88 e (88%).

[(8M)-8-Meeeeeeee-8-ee-8-ee]eeeeeee Meee (‌88‌, M8 = Me, M8 = Me); Meeeeee Meeeeeeee:[‌88‌]

Me e eeee ee 8-eeeeeeee-8-eee (‌88‌, M8 = Me; M = Me; 88 eeee) ee MM8Me8 (88 eM) eee eeeeee eeeee e eeee ee MMMe8•MMM ee MM8Me8 (88 eM) ee ee. Meeee eeeee eeeeeee eee 8 e, eeeeeee (88 eM) eee eeeee. Mee eeeee eeee eee eeee eeeeeeee eeee ee eee–eeeee eeee. eMeMM (888 eeee) eee eeeeee eeeee eee eee eeeeeee eee eeeeeee eee 88 eee. Mee eeeeeee eeeee eee eeeeeeeee eeee eee eeeeeee eeeeeee eeeee, eee eee eeeeee eee eeeeeeeee eeee eeeee eeeeeee (8 × 88 eM). Meeeeeeeeeeee eee eeeeeeeeeeee ee eee eeeeeeee eeeeeeee (88°M/8.8 Meee) eeee M-(8-eeeeeeeee)eeeeeeee ‌88‌ (M8 = Me; M = Me); eeeee: 88%.

Me e eeee ee M-(8-eeeeeeeee)eeeeeeee ‌88‌ (M8 = Me; M = Me; 8.8 eM, 8.8 eeee) ee Me8M (8 eM) eee eeeee e 8 M eeee ee MeMe ee Me8M (8.8 eM, 8.8 eeee) ee −88°M. Meeee eeeee eeeeeee eee 88 eee, eee eeeeeee eee eeeeee eeeeee ee ee eee eeeeeee eee ee eeeeeeeeee 88 eee. M8M (88 eM) eee eeeee eee eee eeeeeee eee eeeeeeeee eeee Me8M. Mee eeeeeeee eeeeeeee eeee eeeeee eeee M8M eee eeeee (MeMM8). Mee eeeee eeeeeee eeeeeeee ee eeeeeeeeeeeee eee ee eeeeeeee eeee eee eee eeee eeeeeeee.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 88/8e, 888.