Olefin Oxidations with Excited Singlet Molecular Oxygen

Abstract

COMMUNICATIONS TO THE EDITOR 3879 dium-on-charcoal catalyst resulted in the uptake of four molar equivalents of gas. Without isolation the presumed 4-amino-3-indolylmethanol (VIII) was treated with potassium nitrosodisulfonate to furnish the desired indoloquinonecarbinol IX [m.p. 85.5-86.5', Amax 231, 287, 350, and 460 mp (e 17,100, 13,900, 3160, and 1300)].9 The carbinol IX was converted into the carbamate I1 [ m.p. 202-204', Amax 231, 286, 345, and 455 mp (e 18,400, 13,800, 3520, and 1290)] by ammonolysis of the derived phenylcarbonate X [m.p. 115-117', Amax 231, 285, 345, and 455 mp (e 17,700, 13,800, 3260, and 1150) 1. I I 6PS C2HS 111, R1 = COOCzHs, Rz = H IV, R, = Rx = H V, RI = H, R2 = CHI VI, R1 = CHO, Rz CHa VI1 " 1

The DAB-Mn++ cytochemical method revisited: validation of specificity for superoxide.

“…Singlet oxygen is a relatively long-lived and electronically excited state of molecular oxygen (Khan and Kasha, 1970; Wilson and Hastings, 1970;Browne and Ogryzlo, 1965;Corey and Taylor, 1964;Foote and Wexler, 1964). Production of Ol('Ag) after a reaction of H202 and hypochlorous acid (HOCI) Kasha, 1963,1970) and its production by the spontaneous dismutation of a chemical source of Oi-in water (Corey et al, 1987a;Khan, 1970) have been demonstrated.…”

The Quenching of Singlet Oxygen (1Δg) by Transition Metal Chelates

“…Since the initial discovery of singlet oxygen ('A,, '0,) reactions with organic substrates in 1939 (1)-and their rediscovery in 1963 (2), the study of '0, reactions has grown at an explosive rate (3)(4)(5). Commercial interest in singlet oxygen chemistry has now reached a high level because of known involvement, or postulated intervention of '0, in processes such as air pollution, cancer formation, rancidification of edible oils, and deterioration of many polymeric materials (rubbers, plastics, fibers, biopolymers, etc.…”

Photosensitisers – the progression from photodynamic therapy to anti-infective surfaces

“…Mulliken discovered that oxygen in the ground state occurred as a triplet [10,11], then in 1931, Kautsky proposed that singlet oxygen ( 1 O 2 ) formed due to energy transfer from the excited photosensitiser to oxygen [12], which allowed initiation of photodynamic reactions. Further studies by a number of researchers developed the understanding of the processes involved and the currently held theory of the mechanism of action of photosensitisers [13][14][15][16][17][18], detailed in Figure 1. The main photophysical and photochemical processes involved are thought to be similar for all photosensitisers.…”