Metal-free synthesis of gem-silylboronate esters and their Pd(0)-catalyzed cross-coupling with aryliodides

Abstract

An efficient method for the synthesis of gem-silylboronate esters based on transition-metal-free reaction of arylboronic acids and trimethylsilyldiazomethane is developed, and Suzuki–Miyaura cross-coupling of gem-silylboronate esters with aryliodides is described.

Organocatalytic Synthesis of α-Trifluoromethyl Allylboronic Acids by Enantioselective 1,2-Borotropic Migration

“…This method was suitable for the synthesis of (achiral) allylboronic acids, which were used in one-pot allylborations 9,11 or converted to their Bpin derivatives. 12 A similar approach was employed by Molander and co-workers (Figure 1c) for the synthesis of benzylboronic acids from trifluoromethyl diazomethane. 13,14 Arnold and co-workers presented a method for the synthesis of chiral α-CF 3 alkyl-and benzylboron compounds by directed evolution of enzymes.…”

“…This method is based on stoichiometric formation of chiral lithium carbenoid intermediates, and therefore, it is not suitable for the direct synthesis of allylboronic acids. The Ley − and Wang groups (Figure c) reported a homologation method based on diazo carbenoid reagents. This method was suitable for the synthesis of (achiral) allylboronic acids, which were used in one-pot allylborations , or converted to their Bpin derivatives .…”

“…The Ley − and Wang groups (Figure c) reported a homologation method based on diazo carbenoid reagents. This method was suitable for the synthesis of (achiral) allylboronic acids, which were used in one-pot allylborations , or converted to their Bpin derivatives . A similar approach was employed by Molander and co-workers (Figure c) for the synthesis of benzylboronic acids from trifluoromethyl diazomethane. , Arnold and co-workers presented a method for the synthesis of chiral α-CF 3 alkyl- and benzylboron compounds by directed evolution of enzymes. , Fluorinated organoboronates are useful reagents for selective synthesis of organofluorines. − The CF 3 motif very often occurs − in pharmaceuticals and agrochemical products (Figure d). − …”

Palladium‐Catalyzed Benzylic Silylation of Diarylmethyl Carbonates with Silylboranes under Base‐Free Conditions

“…The benzyl silane moiety in the product can be a useful synthetic handle for further manipulations under suitable fluoride‐mediated conditions (Scheme 3). The CsF/18‐crown‐6‐promoted allylation and benzylation with allyl bromide and benzyl bromide were possible to afford the allylated 4 and benzylated 5 in 85 and 77 % yields, respectively [16a,b] . The same conditions were applicable to the arylation reaction with phthalonitrile to deliver the corresponding triarylmethane 6 in a good yield [16c] …”

Understanding the Reactivity of Trimethylsilyldiazoalkanes Participating in [3+2] Cycloaddition Reactions towards Diethylfumarate with a Molecular Electron Density Theory Perspective

“…Since the last decade, trimethylsilyldiazomethane [1] has been a popular synthetic reagent owing to its commercial availability. This mild, safe, and efficient alternative has been used for the esterification of naturally occurring carboxylic acids [1,2], preparation of silylenol ethers [3], synthesis of gem-silylboronate esters [4], and ring expansion reactions [5], while one of the most important applications of trimethylsilyldiazoalkanes is the generation of functionalized pyrazolines from [3+2] cycloaddition (32CA) reactions with alkene derivatives [6,7] (Scheme 1). In 1989, Hwu and Wang [8] reviewed the steric influence of trimethylsilyl group in organic synthesis, and subsequently in 1990, Padwa and Wannmaker [9] studied the steric control of trimethylsilyl group on the 32CA reactions of diazoalkanes with trimethylsilyl substituted alkynes.…”