Acceptorless double dehydrogenative
cross-coupling of secondary
and primary alcohols under nickel catalysis is reported. This Guerbet
type reaction provides an atom- and a step-economical method for the
C-alkylation of secondary alcohols under mild, benign conditions.
A broad range of substrates including aromatic, cyclic, acyclic, and
aliphatic alcohols was well tolerated. Interestingly, the C-alkylation
of cholesterol derivatives and the double C-alkylation of cyclopentanol
with various alcohols were also demonstrated.
Here we report the first base-metal catalyzed dehydrogenative coupling of primary (aromatic, heteroaromatic, and aliphatic) and secondary alcohols with methyl-N-heteroaromatics to form various C(sp3)-alkylated N-heteroaromatics.
Herein,
we report an iron-catalyzed, convenient, and expedient
strategy for the synthesis of styrene and naphthalene derivatives
with the liberation of dihydrogen. The use of a catalyst derived from
an earth-abundant metal provides a sustainable strategy to olefins.
This method exhibits wide substrate scope (primary and secondary alcohols)
functional group tolerance (amino, nitro, halo, alkoxy, thiomethoxy,
and S- and N-heterocyclic compounds) that can be scaled up. The unprecedented
synthesis of 1-methyl naphthalenes proceeds via tandem methenylation/double
dehydrogenation. Mechanistic study shows that the cleavage of the
C–H bond of alcohol is the rate-determining step.
The
development of new catalytic processes based on abundantly
available starting materials by cheap metals is always a fascinating
task and marks an important transition in the chemical industry. Herein,
a nickel-catalyzed acceptorless dehydrogenative coupling of alcohols
with nitriles followed by decyanation of nitriles to access diversely
substituted olefins is reported. This unprecedented CC bond-forming
methodology takes place in a tandem manner with the formation of formamide
as a sole byproduct. The significant advantages of this strategy are
the low-cost nickel catalyst, good functional group compatibility
(ether, thioether, halo, cyano, ester, amino, N/O/S heterocycles;
43 examples), synthetic convenience, and high reaction selectivity
and efficiency.
Sustainable chemical production requires fundamentally new types of catalysts and catalytic technologies. The development of coherent and robust catalytic systems based on earth-abundant transition metals is essential; however extremely challenging....
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.