Hassner reaction

Azirines are also made by carbene addition to nitriles (89 — 90) and by thermal or photochemical (68JA2869) elimination of N2 from vinyl azides (e.g. 91 — 92). Vinyl azides are prepared by the Hassner reaction (68JOC2686, 71ACR9), where iodine azide is first added to an alkene and the resultant (3-iodoazide is dehydrohalogenated with base (Scheme 37) (86RTC456). 

CARRUTHERS Cycloaddition Reactions in Organic Synthesis GAWLEY AUBE Principies of Asymmetric Synthesis HASSNER STUMER Organic Syntheses based on Name Reactions and Unnamed Reactions... 

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. 

HASSNER STUMER Organic Syntheses Based on Name Reactions and Unnamed Reactions... 

Hassner, A. and Stumer, C., Organic Syntheses Based on Name Reactions and Unnamed Reactions, Elsevier Science, Oxford, 1994. East, M. B. and Ager, D. J., Desk Reference for Organic Chemists, Krieger Publishing, Malabar, FL, 1995, Chap. 4. 

Hassner, A. Stumer, C. Organic Syntheses Based on Name Reactions, 2nd ed. Pergamon Amsterdam, 2002 p 17. 

A transannular solvent participation has instead been observed in the IN3 addition in CH3CN to tricyclo[4.2.2.02-5]deca-3,7-diene derivatives 62 and 63, which give adducts 64 and 65 as well as tetrazoles 66 and 67 via Hassner-Ritter reaction (equation 69). 

An alternative and elegant approach to bicyclo[3.3.0]isoxazolidines from alkenyl oximes was developed by Grigg (205) and applied in asymmetric reactions by Hassner et al. (206-209) and others (210). The optically active L-serine derived oxime 130 was proposed to be in a thermal tautomeric equilibrium with the nitrone tautomer 131, which underwent an intramolecular 1,3-dipolar cycloaddition to form the product 132 in 80% yield as a single stereoisomer (Scheme 12.44) (209). 

As a synonym of site-selectivity, locoselectivity was used, apparently only by a single author, for designating that site out of several possibilities, where chemical reactions occurs 8. Hassner s regioselectivity was preceded by Viehe s proposal directiospecific9 that did not prevail. 

A. Hassner, C. Stumer, Organic Syntheses Based on Name Reactions and Unnamed Reactions, Pergamon, Oxford, 1994 ... 

HASSNER STUMER Organic Syntheses based on Named Reactions and Unnamed Reactions LEVY TANG The Chemistry of C-Glycosides LI GRIBBLE Palladium in Heteroaryl Synthesis McKILLOP Advanced Problems in Organic Reaction Mechanisms... 

A. Hassner and C. Stumer, Organic Syntheses Based on Name Reactions and Unnamed Reactions, Elsevier, Oxford, 1994, p. 100. See also M. Fieser, Fieser and Fieser s Reagents for Organic Synthesis, Vol. 16, Wiley, New York, 1992, p. 362. 

Regiospecijic is a term introduced by A. Hassner, J. Org. Chem., 33, 2684 (1968). If bonds can be made or broken in two or more different orientations but only one of the possible isomers is formed, the reaction is regiospecific. If there is a significant preponderance of one isomer formed, Hassner calls that reaction regioselective. Most workers use only the former term with qualifying adjectives such as high or low. ... 

Makhluf J. Haddadin was born in Main, Jordan. He holds B.S. and M.S. degrees (Professor C. H. Issidorides) from the American University of Beirut and a Ph.D. degree from the University of Colorado, USA (Professor A. Hassner). He was a research fellow at Harvard University (Professor L. F. Fieser). The art of heterocyclic chemistry has been his main hobby as he worked on heterocyclic steroids, isobenzofurans, isoindoles, quinoxaline 1,4-dioxides (the Beirut reaction), pyridazines, tetrazines, 277-indazoles, and other heterocycles. He rejoined his alma mater in 1964 and currently serves as professor of chemistry. He was vice-president for academic affairs (1987-99). 

Addition of pseudohalogens, such as BrNs and INS, to unsaturated compounds has been shown to occur either by a free radical (via N3) or by an electrophilic (via X+) stepwise mechanism, depending on the reaction conditions (Hassner and Boerwinkle, 1969). Electrophilic addition of BrNs to l-phenylpropyneisnon-regiospecifio (Hassner, 1909) and both products 50 and 51 are formed. The addition of IN3 is instead... 

Hassner and Belinka118 generated primary enamines in situ by reaction of vinyl azides 67 with alkyl lithium derivatives and converted them to ketones (equation 45). 

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