Abstract
A stepwise build-up of multi-substituted C(sp)TJ0VL(3)X carbon centers is an attractive, conceptually simple, but often synthetically challenging type of disconnection. To this end, this report describes how gem-alpha,alpha-dimetalloid-substituted benzylic reagents bearing boron/silicon or boron/tin substituent sets are an excellent stepping stone towards diverse substitution patterns. These gem-dimetalloids were readily accessed, either by known carbenoid insertion into C-B bonds or by the newly developed scalable deprotonation/metallation approach. Highly chemoselective transformations of either the C-Si (or C-Sn) or the C-B bonds in the newly formed gem-C-sp (3) centers have been achieved through a set of approaches, with a particular focus on exploiting the synthetically versatile polarity reversal in organometalloids by lambda(3)-aryliodanes. Of particular note is the metal-free arylation of the C-Si (or C-Sn) bonds in such gem-dimetalloids via the iodane-guided C-H coupling approach. DFT calculations show that this transfer of the (alpha-Bpin)benzyl group proceeds via unusual [5,5]-sigmatropic rearrangement and is driven by the high-energy iodine(iii) center. As a complementary tool, the gem-dimetalloid C-B bond is shown to undergo a potent and chemoselective Suzuki-Miyaura arylation with diverse Ar-Cl, thanks to the development of the reactive gem-alpha,alpha-silyl/BF3K building blocks.
Original language | English |
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Pages (from-to) | 10514-10521 |
Number of pages | 8 |
Journal | Chemical Science |
Volume | 12 |
Issue number | 31 |
Early online date | Jul 2021 |
DOIs | |
Publication status | Published - 21 Aug 2021 |
Keywords
- Cross-coupling reactions
- Esters
- 1,1-diborylalkanes
- Substitution
- Generation
- Reactivity