Asymmetric Diboration of Terminal Alkenes with a Rhodium Catalyst and Subsequent Oxidation: Enantioselective Synthesis of Optically Active 1,2‐Diols

Abstract

Eine enantioselektive Diborierung von terminalen Alkenen mit chiralem 1 und Bis(pinakolato)dibor (B2pin2) wurde entwickelt. Die anschließende Oxidation des Dibor‐Addukts mit Natriumperoxoborat ergab die entsprechenden optisch aktiven 1,2‐Diole mit hohen Ausbeuten und Enantioselektivitäten.

Iterative protecting group-free cross-coupling leading to chiral multiply arylated structures

“…We first chose to examine the reactivity of 1,2 diboronates ( 5 ), which contain both a linear and a branched benzylic boron substituent. These compounds can be easily prepared with high enantioselectivity by diboration of the corresponding styrene derivative 4 (refs 32 , 33 , 34 ). Pinacol substituents were chosen on boron, as these are among the most common and stable ancillary groups for boron 8 35 .…”

Chiral Ion‐Pair Organocatalyst‐Promoted Efficient Enantio‐selective Reduction of α‐Hydroxy Ketones

“…Various electron‐rich as well as electron‐deficient aromatic α‐hydroxy ketones 1 with different substitution patterns furnished the resulting diols 6 with good yields and enantioselectivities. The absolute configuration of the aromatic 1,2‐diols 6 has been determined to be (S) by comparing the optical rotation values with those re‐ported in the literature . Interestingly, electron‐rich α‐hydroxy ketones ( 1 d and 1 e ) gave inferior enantioselectivties but still in good yields, halogenated, substrates gave better results.…”

Synthesis of anti-vicinal diboronates from diarylethynes and B2pin2

“…The borylation of unsaturated substrates, such as the base-promoted boronation of alkynes, is one of the most effective ways to synthesize polyboronates [8][9][10][11][12][13]. Nevertheless, the synthesis of vicinal alkyl diboronates from alkynes is underexplored, whereas the synthesis of vicinal diboronates from alkenes is well known [14][15][16][17].…”