Journal of the American Chemical Society p. 13614 - 13621 (2011)
Update date:2022-09-26
Topics:
Ley, David
Gerbig, Dennis
Wagner, J. Philipp
Reisenauer, Hans P.
Schreiner, Peter R.
Cyclopropylhydroxycarbene was generated by high-vacuum flash pyrolysis of cyclopropylglyoxylic acid at 960 °C. The pyrolysis products were matrix-isolated in solid Ar at 11 K and characterized by means of IR spectroscopy. Upon photolysis, the carbene undergoes ring expansion, thereby paralleling the reactivity of other known cyclopropylcarbenes. The ring expansion product, cyclobut-1-en-1-ol, was characterized for the first time. Matrix-isolated cyclopropylhydroxycarbene undergoes [1,2]H-tunneling through a barrier of approximately 30 kcal·mol-1, yielding cyclopropylcarboxaldehyde. The cyclopropyl moiety acts as a π-donor and increases the half-life by almost a factor of 10 compared to parent hydroxymethylene, resulting in a temperature-independent half-life of τ = 17.8 h at both 11 and 20 K. Hence, cyclopropylhydroxycarbene is the first hydroxycarbene that differs from other members of its family by a significantly prolonged half-life. As expected, the O-deuterated analogue does not show tunneling. Our findings are rationalized by accurate CCSD(T)/cc-pVnZ (n = D, T)//M06-2X/6-311++G(d,p) computations. The half-life of cyclopropylhydroxycarbene was verified by tunneling computations employing the Wentzel-Kramers-Brillouin formalism. By comparison with other experimentally known hydroxycarbenes, we determine the electronic donor capabilities of the carbenes' substituents to be a dominant factor governing their half-lives.
View MoreXinji City Taida Sinopec Co., Ltd.
Contact:0086-311-85341278
Address:No.6, Nanhua Road,Xinji City Road,Hebei Province,China
Nanjing Chemipioneer Pharma&Tech Co.,Ltd
website:http://www.chemipioneer.com.cn
Contact:+86-25-52685700
Address:Room 305,A Block,Biological-Medicine Building,Business Start-up Center,Xin-ke 1st Road, High-tech development zone,Nanjing city,Jiangsu Province, China
Contact:+86-0760-85282375
Address:zhongjing road,zhongshan torch hi-tech industrial development zone
Changzhou Litong Chemical Co., Ltd.
website:http://www.litonchem.com/
Contact:+86-519-86301238
Address:Laoba Rd, Hutang town Changzhou Jiangsu
Shanghai Dianyang Industry Co.,ltd
Contact:+86 21 6492 4669
Address:Chejing RD, Songjiang District, Shanghai, China
Doi:10.1021/acs.orglett.5b00650
(2015)Doi:10.1016/j.tetlet.2015.01.155
(2015)Doi:10.1021/ol201426c
(2011)Doi:10.1039/c8cc03600d
(2018)Doi:10.1016/S0957-4166(00)86344-2
(1990)Doi:10.1039/c1ob05247k
(2011)