ChemInform Abstract: THE PHOTOLYSIS OF 2‐PHENYLTHIETANE 1,1‐DIOXIDES, PREPARATION OF SUBSTITUTED CYCLOPROPANES

Finlay, John D.; Smith, David J.; Durst, Tony

doi:10.1002/chin.197850142

Cited by 1 publication

(1 citation statement)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most common process after a-cleavage is bond formation at the oxygen atom to form the corresponding sulfenates, RS-OR 0 . [54] and 88 [55] give the photoelimination and CÀC bond-formation products 87 and 89, respectively, in yields that vary from 88% to 95%. In contrast, when the sulfone moiety is part of a lactam (90), the formation of b-lactam 91 occurs in only 10% yield.…”

Section: Photoelimination Of Co 2 From Lactonesmentioning

confidence: 99%

CarbonCarbon Bond Formation by the Photoelimination of Small Molecules in Solution and in Crystals

Shiraki

2009

Handbook of Synthetic Photochemistry

View full text Add to dashboard Cite

The formation of CÀC bonds is arguably the most important reaction in organic synthesis. While many strategies have been developed to link organic fragments with a wide range of thermal processes, photochemical syntheses based on the elimination of a small molecule, X (Scheme 2.1), offer significant advantages when the desired structures are highly strained or hindered. In this chapter, we will describe examples of the generation of CÀC bonds through the photoinduced extrusion of small molecules such as N 2 , CO 2 , CO, and SO 2 , as well as the formal extrusion of S atoms. After describing the most general mechanistic aspects covering these reactions and the current scope and limitations, we will illustrate examples involving these reactions in solution. Following that, we will describe a strategy based on the use of crystalline solids that helps to control the fate of the reaction intermediates. Finally, we will illustrate the use of crystalline ketones (X¼CO) as one of the most promising general methods for the synthesis of compounds with all-carbon adjacent stereogenic quaternary centers.The photoelimination of a small stable molecule X accompanied by the formation of a new CÀC bond could, in principle, take place in a concerted manner through cyclic transition states with simultaneous bond-breaking and bond-making steps that follow trajectories determined by orbital symmetry considerations. However, as it pertains to photodecarbonylation reactions, theoretical analysis on the formation of hydrogen and CO from formaldehyde suggests that the concerted process is significantly less likely than the stepwise cleavage of the HÀC(O)ÀH bonds [1]. Similar conclusions have been made for the elimination of N 2 and H 2 from simple diazene (HN¼NH) [2]. In fact, evidence for concerted reactions is available only in a handful of cases (vide infra). Most examples involve a four-step process that starts with electronic excitation (step 1) and is followed by an a-cleavage reaction (step 2) to give a primary biradical or radical pair (BR-1). Subsequent dissociation of the small molecule X (step 3) results in the formation of the secondary biradical or radical pair (BR-2), which is followed by radical-radical combination to give the desired product (step 4).Handbook of Synthetic Photochemistry. Edited

show abstract

Section: Photoelimination Of Co 2 From Lactonesmentioning

confidence: 99%

CarbonCarbon Bond Formation by the Photoelimination of Small Molecules in Solution and in Crystals

Shiraki

2009

Handbook of Synthetic Photochemistry

View full text Add to dashboard Cite

show abstract

ChemInform Abstract: THE PHOTOLYSIS OF 2‐PHENYLTHIETANE 1,1‐DIOXIDES, PREPARATION OF SUBSTITUTED CYCLOPROPANES

Abstract: 2‐Phenylthietan (I) wird mit Peressigsäure zum Sulfon (II) oxidiert und nach Metallierung mit Butyllithium zu 2‐substituierten 2‐Phenylthietan‐1, l‐dioxiden (III) alkyliert.

Cited by 1 publication

References 1 publication

CarbonCarbon Bond Formation by the Photoelimination of Small Molecules in Solution and in Crystals

CarbonCarbon Bond Formation by the Photoelimination of Small Molecules in Solution and in Crystals

Contact Info

Product

Resources

About