Ni‐Catalyzed Reductive Allylation of Unactivated Alkyl Halides with Allylic Carbonates

Abstract

Game of two electrophiles: Two partially positively charged sp(3) carbon atoms can be connected by using a catalytic Ni species in the presence of an environmentally benign Zn reductant, delivering allylated alkanes. This unprecedented approach allowed a variety of unactivated alkyl halides and substituted allylic carbonates to regioselectively afford E-alkenes in good to excellent yields.

Nickel-Catalyzed Reductive Couplings

“…The Ni-catalyzed reductive coupling protocol enables allylation of a wide set of alkyl halides (Scheme 10) [36][37][38]. The reactions display excellent regioselectivities wherein addition of alkyl groups to the less hindered allylic positions is adopted.…”

“…While most transformations based on activated alkyl electrophiles emphasize C(sp 3 )-C(sp 2 ) bond forming methods (see Sects. 2.2-2.5), the cross-coupling of allylic acetates (or carbonates) with unactivated alkyl halides represents the only example for the construction of hetero C(sp 3 )-C(sp 3 ) bonds utilizing activated alkyl electrophiles [36][37][38].…”

Mild and Phosphine-Free Iron-Catalyzed Cross-Coupling of Nonactivated Secondary Alkyl Halides with Alkynyl Grignard Reagents

“…The following known starting materials (alkyl halides and terminal alkynes) were prepared according to the literature procedures: [2][3][4][5][6][7][8][9][10][11][12][13] …”

“…Yields reported in the publication are of isolated materials. All 3-iodononane [2] 5-iodononane [2] I 2-iodo-2,3-dihydro-1H-indene [3] I iodocycloheptane [4] I 6-iodo-2-methylhept-2-ene [5] I 6-iodo-2-methylhept-2-ene [5] I (3-iodobutyl)benzene [5,6] I (2-iodobutyl)benzene [2] O I 4-iodotetrahydro-2H-pyran [7] BocN I…”

Nickel‐Catalyzed Reductive Benzylation of Aldehydes with Benzyl Halides and Pseudohalides

“…When MgCl 2 was not added to the reaction mixture, the yield decreased significantly, demonstrating that the presence of this salt is necessary for the reaction to progress (Table 1, entry 8). [21] When other metal halides such as ZnCl 2 , LiCl, and MgBr 2 were employed as the additive instead of MgCl 2 , a sharp decrease in the reaction yield was observed (Table 1, entries 9-11). In the absence of reducing agent the reaction did not proceed, demonstrating that the presence of Zn is also essential (Table 1, entry 12).…”