Stereoselective Synthesis of Six-Membered Carbocycles

Muriel Amatore, Corinne Aubert, Marion Barbazanges, Marine Desage-El Murr, and Cyril Ollivier 

Sorbonne Universites, UPMC Univ Paris 06, Institut Parisien de Chimie Moleculaire (IPCM UMR CNRS 8232), Paris, France 

Stereoselective Multiple Bond-Forming Transformations in Organic Synthesis, First Edition. Edited by Jean Rodriguez and Damien Bonne. 

2 METAL-CATALYZED STEREOSELECTIVE MULTIPLE BOND-FORMING TRANSFORMATIONS 

1 [2+2+2] Cycloadditions Several metals are known to trigger stereoselective [2-I-2-I-2] cycloaddition of polyunsaturated systems [3] and this approach has been applied to different types of unsaturated substrates. In this general overview, most cited examples will focus on cobalt, nickel, and rhodium catalysis. 

---

Hassner and coworkers reported a one-pot protocol for the stereoselective synthesis of isoxazolines fused to five- and six-membered carbocycles 204 (Scheme 49) [151]. The method involves conjugate addition of Grignard... 

Hassner and coworkers have developed a one-pot tandem consecutive 1,4-addition intramolecular cycloaddition strategy for the construction of five- and six-membered heterocycles and carbocycles. Because nitroalkenes are good Michael acceptors for carbon, sulfur, oxygen, and nitrogen nucleophiles (see Section 4.1 on the Michael reaction), subsequent intramolecular silyl nitronate cycloaddition (ISOC) or intramolecular nitrile oxide cycloaddition (INOC) provides one-pot synthesis of fused isoxazolines (Scheme 8.26). The ISOC route is generally better than INOC route regarding stereoselectivity and generality. 

Miscellaneous Gold- and Iron-Catalyzed Cascade Reactions The car-benic reactivity of gold catalysis was exploited toward the synthesis of stereoselective six-membered ring carbocycles, through cyclopropanation reactions incorporated in cascade sequences [31]. 

---