Catalytic Reductive Vinylidene Transfer Reactions - Journal of the

Communication pubs.acs.org/JACS

Catalytic Reductive Vinylidene Transfer Reactions Sudipta Pal,‡ You-Yun Zhou,‡ and Christopher Uyeda* Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States S Supporting Information *

Table 1. Catalyst Structure−Activity Relationshipsa

ABSTRACT: Methylenecyclopropanes are important synthetic intermediates that possess strain energies exceeding those of saturated cyclopropanes by >10 kcal/ mol. This report describes a catalytic reductive methylenecyclopropanation reaction of simple olefins, utilizing 1,1-dichloroalkenes as vinylidene precursors. The reaction is promoted by a dinuclear Ni catalyst, which is proposed to access Ni2(vinylidenoid) intermediates via CCl oxidative addition.

V

inylidenes (methylidene carbenes) are reactive intermediates comprising a divalent carbon atom incorporated into

entry

catalyst

yield

E/Z ratio

1 2 3b 4b 5b 6 7 8 9

[i‑PrNDI]Ni2(C6H6) (1) [i‑PrNDI]Ni2Cl2 (4) i‑Pr NDI (5) + Ni(DME)Cl2 Et NDI (6) + Ni(DME)Cl2 Me NDI (7) + Ni(DME)Cl2 [i‑PrPDI]NiCl2 (8) [i‑PrIP]Ni(COD) (9) [BPY]Ni(COD) (10) [i‑PrDAD]Ni(COD) (11)

94% 87% 92% 50%