Borylation of Unactivated Aryl Chlorides under Mild Conditions by Using Diisopropylaminoborane as a Borylating Reagent

Abstract

The synthesis of arylboronic ester derivatives from aryl chlorides by using aryl(amino)boranes is described. Palladium-catalyzed coupling between aryl chlorides and diisopropylaminoborane leads to the formation of a CB bond under mild conditions. A wide range of functional groups are tolerated, making this method particularly useful for the borylation of functionalized aromatics.

Catalytic Double Carbon–Boron Bond Formation for the Synthesis of Cyclic Diarylborinic Acids as Versatile Building Blocks for π‐Extended Heteroarenes

“…Unfortunately, however, reactions under these optimized conditions using DPEPhos failed to promote the borylation of dibromide 3 b . Reoptimization of the reaction conditions showed that using KI together with CyJohnPhos, markedly improved the yield of 1 b , affording product 1 b in 97 % NMR yield (entry 2, see also the Supporting Information (SI) for details of optimization and some discussion regarding the effect of KI) …”

“…This highlights the synthetic advantage of our protocol over previously reported methods using organolithium reagents . In particular, the tolerance of an aryl chloride moiety, as shown for 1 k , is notable when considering that the report that the borylation of aryl chlorides occurs with 4 a using a Pd/XPhos catalyst . Our protocol also allowed the synthesis of π‐extended analogue 1 p as well as diarylborinic acids containing nitrogen ( 1 q ) and sulfur ( 1 r ) tethers.…”

Fluorinated Aryl Boronates as Building Blocks in Organic Synthesis

“…The transition metal‐catalyzed C−X (X=Cl, Br, I, OTf) borylation reaction provides another option for introducing boronate ester groups selectively into fluorinated aryl halides or triflates [60–70] . Masuda et al .…”

“…Several examples of transition metal‐catalyzed C−X borylation reactions generating products with the C−B moiety located ortho , meta , and para to the fluorine substituents have been reported [58,63–67,69] . For example, in 2014, Pucheault et al .…”

Indolylboronic Acids: Preparation and Applications

“…The typical borylation setup makes use of aryl/hetaryl halides, borylation reagents, and transition metal catalysts. Both iodide and chloride are able to couple with either pinB-Bdan [49] or diisopropylaminoborane [50] under palladium catalysis conditions (Table 1, entries 1 and 2). The isolated yields of indolylboronates ranged from 47−85%.…”