Rh(II)-catalyzed reaction of alpha-diazocarbonyl compounds bearing beta-trichloroacetylamino substituent: C-H insertion versus 1,2-H shift.
The Rh(II)-carbene reaction is dramatically affected by the neighboring substituents. If the neighboring substituent is an OH group, a1,2-H shift is the exclusive pathway. If it is an OAc group, a 1,2-acetoxy migration is observed. If it is p-toluenesulfonyl group, 1,3 and 1,5-C-H insertion are the major pathways, and the 1,2-H shift is completely suppressed. If the adjacent substituent is a trichloroacetyl amino group, 1,5-C-H insertion competes with the 1,2-hydride shift, and no 1,3-C-H insertion can be observed. Both electronic and steric factors are responsible for the switching of the Rh(II)-carbene reaction pathway. The highly stereoselective 1,5-C-H insertions in Rh(II)-catalyzed reaction of alpha-diazocarbonyl compounds, bearing beta-trichloroacetylamino substituent, can be utilized as a novel way to synthesize five-membered cyclic beta-amino acid derivatives.
Zhang
Zhenhua
Z
Beijing National Laboratory of Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, P.R. China.
Shi
Weifeng
W
Zhang
Jian
J
Zhang
Bo
B
Liu
Bingge
B
Liu
Yiyang
Y
Fan
Bo
B
Xiao
Fengping
F
Xu
Feng
F
Wang
Jianbo
J
D000596:Amino Acids / Q000737:chemistry; D001391:Azo Compounds / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008968:Molecular Conformation; D012238:Rhodium / Q000737:chemistry*
D000596:Amino Acids; D001391:Azo Compounds; C030011:carbene; D012238:Rhodium; D008697:Methane