Copper‐Mediated One‐Pot Transformation of 2‐N‐Sulfonyl‐ aminoaryl Diselenides into Benzo[b][1,4]selenazines

Copper(II) Trifluoromethanesulfonate

“…[1,4]selenazines has been developed (eq 57). 51 The product arises from a [ The title compound is an efficient catalyst for the synthesis of various polycyclic arenes, such as naphthalenes and tetrahydroanthracenes, from 2-alkenylphenyl ketones and aldehydes (eq 58). 52 The cyclization can also be performed using TfOH as catalyst.…”

A One‐Pot Access to Benzo[b][1,4]selenazines from 2‐Aminoaryl Diselenides

“…As part of our research on Diels–Alder reactions and the applications of electron‐poor chalcogen‐containing heterodienes, we recently reported a simple procedure for the preparation of benzo[ b ][1,4]selenazines from 2‐ N ‐sulfonylaminoaryl diselenides based on the Cu II ‐catalysed generation of o ‐iminoselenones, a new class of transient electron‐poor heterodienes. The procedure allowed the effective isolation of benzofused selenium‐containing heterocycles under quite mild reaction conditions, with complete consumption of both of the selenium‐containing subunits of a diselenide.…”

“…The procedure allowed the effective isolation of benzofused selenium‐containing heterocycles under quite mild reaction conditions, with complete consumption of both of the selenium‐containing subunits of a diselenide. The mechanism showing how this could be achieved is given in Scheme . Thus, copper(II) activation of the Se–Se bond of the parent 2‐ N ‐sulfonylaminoaryl diselenide (i.e., 1a ), followed by base‐mediated 1,4‐elimination at selenium of selenolate anion 2a , generates o ‐iminoselenoquinone 3a .…”

Copper‐Mediated One‐Pot Access to 2,3‐Dihydrobenzo[b][1,4]oxathiines from o,o′‐Dihydroxydisulfides

“…We have recently reported that transient dienic o ‐iminothioquinones (and o ‐iminoselenoquinones ) can be obtained from the corresponding o , o ′‐di‐ N ‐tosylaminodisulfides (or o , o ′‐di‐ N ‐tosylaminodiselenides) through a copper‐mediated 1,4‐elimination at sulfur (or selenium). The latter species can be trapped in an IEDDAR to give, under mild reaction conditions, 2,3‐dihydrobenzo[ b ][1,4]thiazines (and 2,3‐dihydrobenzo[ b ][1,4]selenazines ). The scope and extension of this new method to the preparation of o ‐thioquinones 7 is described in this paper.…”

“…In fact, the ability of reacting as electron‐poor dienes with 1,3‐dienes working as dienophiles is typical of o ‐thioquinones and related hetero‐quinoid systems . As in the case of o ‐iminothiones and o ‐iminoselenones produced using this copper‐mediated procedure, no cycloadduct was obtained using phenyl vinyl sulfide 10f as a dienophile. A possible interaction of 10f with the catalyst, thus eliminating those with the disulfide and the consequential 1,4‐elimination at sulfur, cannot be ruled out; however, we demonstrated that reacting 8d in the presence of both 10f and 10a the oxathiine 2h was still isolated albeit in lower yields (51%).…”