Recent advances in asymmetric borylation by transition metal catalysis

Abstract

We provide a comprehensive overview of transition metal-catalysed asymmetric borylation processes to construct C–B, C–C, and other C–heteroatom bonds with considerable attention devoted to the reaction modes and the mechanisms involved.

First-Row d-Block Element-Catalyzed Carbon–Boron Bond Formation and Related Processes

“…Consequently, reports of borylation reactions employing catalyst precursors involving these metals are growing in number and are likely to continue to do so. In particular we anticipate significant opportunities for advances in asymmetric 700 and photocatalyzed borylations 73 using first-row transition metals, as these have largely required second-and third-row metals thus far.…”

On the reactivity of Al-group 11 (Cu, Ag, Au) bonds

“…See ESI ‡ for complete synthetic, quantum chemical and crystallographic details. CCDC codes 2133123 (17), 2133122 (18), 2133127 (19), 2133126, (20), 2133125 (23) and 2133124 (24) ‡ contain the supplementary crystallographic data for this paper.…”

“…[12][13][14][15] In this latter regard, the most significant activity has centred on the exploitation of boron-centred (boryl) moieties as strongly σ-donating ligands to transition metal (TM) centres and their attendant applications in synthesis and C-B bond-forming catalysis. [16][17][18][19] Although the synthetic utility of organoboranes ensures the continuing prominence of TM-boryl complexes, the variations in TM-E bond strength and polarity resulting from comparable species featuring transition metals bonded to heavier group 13 elements (i.e. E = Al, Ga, In or Tl) promises to expand the scope of complementary or contrasting TM-E reactivity.…”

Enantioselective Cobalt‐Catalyzed Hydroboration of Ketone‐Derived Silyl Enol Ethers

“…This is important, considering that enantiopure compounds are required in modern medicinal chemistry [4] . In this context, transition‐metal‐catalyzed asymmetric hydroboration of alkenes has been recognized as one of the most straightforward methods for the preparation of enantiopure organoboron compounds [4d, 5] . Despite the significant advances achieved following the seminal study by Burgess, [6] enantioselective hydroboration of alkenes has been dominated by rhodium and iridium catalysis, [7] and asymmetric hydroboration of olefins catalyzed by earth‐abundant metals has been rarely reported (Figure 1a).…”