
TY  - JOUR
A1  - Crow, WD 
A1  - McNab, H 
T1  - Synthetic Applications of Intramolecular Insertion in Arylcarbenes. II. o-Alkoxy-, Dialkylamino- and Alkylthio-phenylcarbenes
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1979
VL  - 32
IS  - 1
SP  - 99
EP  - 109
KW  - 
UR  - https://doi.org/10.1071/CH9790099 
N2  - A series of phenylcarbenes, substituted in the ortho-position by alkoxy, dialkylamino and alkylthio side chains containing up to three carbon atoms, has been generated in the gas phase and pyrolysed at 250-750º/0.05-0.20mm. Carbene insertion occurs in moderate to high yield to give the appropriate five-and six-membered heterocyclics, the former predominating. The regioselectivity of the carbene insertion (five-membered ring us six-membered ring) is highest in the case of the alkoxy and dialkylamino compounds, where six-membered-ring formation is relatively minor; in the case of the alkylthiophenylcarbenes, the selectivity in favour of the smaller ring is, by comparison, small. The reasons for this are discussed in terms of the geometry of the transition state and the donor capacity of the heteroatom. 
ER  -

