NHC-catalyzed [4+2]

David Lupton and co-worker at Monash University have reported in JACS on an NHC-catalyzed [4+2] reaction.

JACS paper

Dihydropyran access

Carlos Saa and co-workers at Universidad de Santiago de Compostela have reported in ACIE on a reaction involving a ruthenium cascade followed by C-O formation to form dihydropyrans.

ACIE paper

Pyridines from 2H-azirines

Cheol-Min Park and co-workers from Nanyang Technological University in Singapore have reported in ACIE on the synthesis of pyridines from 2H-azirines.

ACIE paper

Juglomycin A synthesis

Rodney Fernandes and co-workers from IIT Bombay have reported in JOC on a chromium carbene approach to access juglomycin.

JOC paper

Pyridine synthesis

Cheol-Min Park and co-workers at Nanyang Technological University have reported in Chem Comm on a method for synthesis of pyridines through N-O bond cleavage using a carbenoid precursor.

Chem Comm paper

Friedel-Crafts cascade

Arun Ghosh and co-workers from Purdue have reported in Organic Letters on a Friedel-Crafts cascade to form a seven membered ring.

OL paper

Loss of diazo group cascade

Claude Spino and co-workers at Universite de Sherbrooke have reported in JACS on a [4+1] cascade.  A loss of a diazo group involved, hmm…reminds me of some of Dale Boger’s work.

JACS paper

Loss of 2 x N2 to form carbenes

Duncan Wardrop and co-worker from the University of Illinois in Chicago have reported in Organic Letters on an interesting approach to form a carbene by presumably forming a tetraazafulvene intermediate, which breaks down to the carbene by losing two molecules of nitrogen (ie:  N2).  At first I wondered how scary this reaction is because of the gain of entropy, but it looks pretty straight forward:  they just add DIC (diisopropylcarbodiimide) to the tetrazole and then load the reaction mixture directly on a column for purification.

OL paper

Allenoates using NHCs

Jianwei Sun and co-workers at Hong Kong University of Science and Technology have reported in Organic Letters on a carbene catalyzed formation of allenoates.

OL paper

From carbenoid to ring

Jon Njardarson and co-workers at the University of Arizona have reported in Organic Letters on the synthesis of oxygen containing rings from diazocarbene.

OL paper