Diastereotopos-Differentiation in the Rh-Catalyzed Amination of Benzylic Methylene Groups in the alpha-Position to a Stereogenic Center

The diastereoselectivity of the Rh-catalyzed C-H amination was examined with 18 chiral open-chain substrates, which bear a benzylic methylene group in the alpha-position to a stereogenic center (-CHMeX), and with four chiral cyclic tetralins, in which the stereogenic center was positioned at carbon atom C2. The C-H amination was performed using trichloroethoxysulfonyl-substituted amine (H(2)NTces) as the nitrogen source, a diacyloxyiodobenzene as the oxidant, and bis[rhodium(alpha,alpha,alpha',alpha'-tetramethyl-1,3-benzenedipropionate)] [Rh-2(esp)(2)] as the catalyst. For acyclic substrates a high syn diastereoselectivity (dr > 95/5) was found if the substituent X was Br, PO(OEt)(2), SO2Ph, or CIOCCF3 (eight examples). Moderate to good syn selectivities (     «

The diastereoselectivity of the Rh-catalyzed C-H amination was examined with 18 chiral open-chain substrates, which bear a benzylic methylene group in the alpha-position to a stereogenic center (-CHMeX), and with four chiral cyclic tetralins, in which the stereogenic center was positioned at carbon atom C2. The C-H amination was performed using trichloroethoxysulfonyl-substituted amine (H(2)NTces) as the nitrogen source, a diacyloxyiodobenzene as the oxidant, and bis[rhodium(alpha,alpha,alpha',a...     »

ISI Document Delivery No.: 988JT Times Cited: 3 Cited Reference Count: 57 Noerder, Anike Warren, Sarah A. Herdtweck, Eberhardt Huber, Stefan M. Bach, Thorsten Huber, Stefan/F-7660-2011 Deutsche Forschungsgemeinschaft [Ba 1372-12]; TUM Graduate School; Fonds der Chemischen Industrie for a Liebig fellowship This project was supported by the Deutsche Forschungsgemeinschaft (Ba 1372-12) and by the TUM Graduate School. S.M.H. acknowledges the Fonds der Chemischen Industrie for a Liebig fellowship. We thank Dr. Markus Drees (TV Miinchen) for helpful discussions regarding the computation of KIEs. 3 Amer chemical soc Washington     «

ISI Document Delivery No.: 988JT Times Cited: 3 Cited Reference Count: 57 Noerder, Anike Warren, Sarah A. Herdtweck, Eberhardt Huber, Stefan M. Bach, Thorsten Huber, Stefan/F-7660-2011 Deutsche Forschungsgemeinschaft [Ba 1372-12]; TUM Graduate School; Fonds der Chemischen Industrie for a Liebig fellowship This project was supported by the Deutsche Forschungsgemeinschaft (Ba 1372-12) and by the TUM Graduate School. S.M.H. acknowledges the Fonds der Chemischen Industrie for a Liebig fellowship....     »