sp³Bis‐Organometallic Reagents via Catalytic 1,1‐Difunctionalization of Unactivated Olefins

Abstract

A catalytic 1,1‐difunctionalization of unactivated olefins en route to sp3 bis‐organometallic B,B(Si)‐reagents is described. The protocol is characterized by exceptional reaction rates, mild conditions, wide scope, and exquisite selectivity pattern, constituting a new platform to access sp3 bis‐organometallics.

Ni-Catalyzed Reductive Allylation of α-Chloroboronates to Access Homoallylic Boronates

“…α-Haloboronates are multifunctional synthetic precursors in synthetic chemistry that can be converted into valuable complex alkylboronates. Herein we report a Ni-catalyzed reductive allylation of α-chloroboronates with allyl sulfones as allylation reagents to obtain homoallylic boronates (Scheme d).…”

Recent progress in nickel-catalyzed carboboration of alkenes

“…In 2021, Martin and co-workers 38 reported a highly modular and site-selective 1,1-difunctionalization of unactivated olefins with B 2 pin 2 enroute to bis-organometallic B, B- or B, Si-reagents. However, only the B- or Si-activated primary alkyl bromides were suitable for this carboboration reaction system and under slightly different conditions.…”

Nickel-Catalyzed 1,1-Aminoborylation of Unactivated Terminal Alkenes

“…While significant progress has been made by utilizing alkynes and well-defined vinyl boronates as precursors, , we anticipated that a generic platform aimed at streamlining the synthesis of α-aminoboronic acids from a 1,1-difunctionalization of simple and widely available unactivated olefins might represent an attractive scenario. As part of our interest in Ni-catalyzed chain walking, we expected that a protocol consisting of a [1,2]-nickel migration might translocate the metal center adjacent to a boron atom prior to C–N bond formation (Scheme , II ). , At the outset of our investigations, however, it was not clear whether it would be possible to overcome the inherent propensity of unactivated olefins for triggering catalytic 1,2-difunctionalization and to avoid parasitic chain-walking reactions that might enable bond formation at remote, previously unfunctionalized sp 3 reaction sites. Herein, we report the successful implementation of this goal, culminating in a protocol that gives access to a wide variety of α-aminoboronic acid derivatives possessing basic amine functionsan elusive motif when preparing 1,1-aminoboranesfrom simple unactivated olefin precursors via an unorthodox 1,1-difunctionalization event (Scheme , bottom).…”