Synlett 2011(20): 2981-2984  
DOI: 10.1055/s-0031-1289885
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Enantio- and Diastereoselective Nitro-Mannich Reactions with in situ Generated N-Boc-imines Catalyzed by a Bifunctional Thiourea-Guanidine Catalyst

Wei Huanga, Cheng Peng*a,b, Li Guoa, Rong Hub, Bo Han*a
a State Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P. R. of China
Fax: +86(28)61800231; e-Mail: hanbo@cdutcm.edu.cn;
b Ministry of Education Key Laboratory of Standardization of Chinese Medicine, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P. R. of China
Fax: +86(28)61800232; e-Mail: pengchengchengdu@126.com;
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Publication History

Received 22 August 2011
Publication Date:
11 November 2011 (online)

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Abstract

The asymmetric nitro-Mannich reactions of nitroalkanes and in situ generated N-Boc-imines were achieved with a new type of thiourea-guanidine bifunctional organocatalyst. The novel transformations exhibited good diastereoselectivities, and the adducts bearing adjacent chiral centers were generally obtained in moderate to high enantioselectivities (up to 94% ee). This reaction provides a concise and alternative route converting readily accessible and stable N-carbamate amido sulfones into optically active 1,2-diamino compounds.