A Highly Enantio- and Diastereoselective Molybdenum-Catalyzed Asymmetric Allylic Alkylation of Cyanoester

Conditions:
10 mol% Mo(CO)6, 15 mol% ligand, 10 mol% NaH, BSA, THF, 60 deg C
99% yield, 20/1 Branched/Linear, 11/1 dr, 97% ee

Barry M. Trost, John R. Miller, and Christopher M. Hoffman, Jr
J. Am. Chem. Soc., 2011, 133, 8165–8167

DOI: 10.1021/ja2029602

Summary: An efficacious Mo-catalyzed enantioselective allylation of various cyanoester nucleophiles provided a number of highly functionalized branched cyanoesters containing a quaternary carbon stereocenter.  This synthetic method generates the desired allylic cyanoesters products with high yield, chemoselectivity, diastereoselectivity and enantioselectivity.

Rhodium-Catalyzed Reductive Cleavage of Carbon−Cyano Bonds with Hydrosilane: A Catalytic Protocol for Removal of Cyano Groups

Mamoru Tobisu, Ryo Nakamura, Yusuke Kita and Naoto Chatani

J. Am. Chem. Soc., 2009, 131, 3174–3175

DOI: 10.1021/ja810142v

Summary: Recently, transition metal activation of the C-CN bond has been an area of intense synthetic activity. Much of the previous work has been centered around Ni(0) mediated C-C bond formation. The Chatani group has developed a rhodium-catalyzed hydrosilane mediated reductive cleavage of the C−CN bond. The reaction has a large synthetic scope including decyanation of aryl- and alkyl nitriles. Additionally, the reaction has a very good functional group tolerence and can be performed in the presence of ester, ether, amino and amide groups. This synthetic method was also demonstrated in several examples where a cyano group was present as a removable ortho-directing group (via a C-H functionalization process).