Markovnikov vinylborinates

Soderquist and coworkers [21] have reported the facile oxidation of B-R-9-BBN with anhydrous trimethyl-N-oxide (TMANO), which is both highly selective and efficient. The resulting borinates resist further oxidation with this reagent and are also remarkably stable toward further oxidation in the open air. These alkylborinates react [20] with a-methoxyvinyllithium (LiAMV, 1.64 equiv) and lead to the quantitative formation of the stable ate complexes. The smooth migration of the alkyl group takes place when ate complexes are treatment with borontrichloride (1.3 equiv) and produce the corresponding Markovnikov vinylborinates (Scheme 20.7) [20]. 

Table 20.8 Preparation of Markovnikov vinylborinates (8) from B-alkyl-OBBD derivatives [20] ...

The Markovnikov vinylborinates prepared from 9-oxa-10-borabicyclo[3.3.2] decanes undergo facile Suzuki coupling to alkylbromide and provide unsym-metrical 1,1-disubstituted alkenes (Table 31.8 Eq. 31.6) [5]. 

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