Synthesis of a simplified version of stable bulky and rigid cyclic (alkyl)(amino)carbenes, and catalytic activity of the ensuing gold(I) complex in the three-component preparation of 1,2-dihydroquinoline derivatives.
A 95/5 mixture of cis and trans 2,4-dimethyl-3-cyclohexenecarboxaldehyde (trivertal), a common fragrance and flavor material produced in bulk quantities, serves as the precursor for the synthesis of a stable spirocyclic (alkyl)(amino)carbene, in which the 2-methyl-substituted cyclohexenyl group provides steric protection to an ensuing metal. The efficiency of this carbene as ligand for transition metal based catalysts is first illustrated by the gold(I) catalyzed hydroamination of internal alkynes with secondary dialkyl amines, a process with little precedent. The feasibility of this reaction allows for significantly enlarging the scope of the one-pot three-component synthesis of 1,2-dihydroquinoline derivatives, and related nitrogen-containing heterocycles. Indeed, two different alkynes were used, which include an internal alkyne for the first step.
Zeng
Xiaoming
X
UCR-CNRS Joint Research Chemistry Laboratory (UMI 2957), Department of Chemistry, University of California Riverside, Riverside, California 92521-0403, USA.
Frey
Guido D
GD
Kinjo
Rei
R
Donnadieu
Bruno
B
Bertrand
Guy
G
D000447:Aldehydes / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D002384:Catalysis; D053138:Cyclohexenes / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008697:Methane / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry; D011804:Quinolines / Q000138:chemical synthesis*
D000447:Aldehydes; D000480:Alkynes; D000588:Amines; D053138:Cyclohexenes; D009942:Organometallic Compounds; D011804:Quinolines; C030011:carbene; D006046:Gold; D008697:Methane