Phenyliodine(III) Diacetate/I₂‐Mediated Domino Approach for Pyrrolo[1,4]Thiazines and 1,4‐Thiazines by a One‐Pot Morin Rearrangement of N,S‐Acetals

Abstract

An efficient domino transformation using a phenyliodine(III) diacetate (PIDA)/I2 combination towards Morin 1,4‐thiazine compounds has been developed starting from N,S‐acetals. The latter leads to “one‐step” regioselective methylene insertion without the need for traditional sulfoxide intermediates in good yields. The reaction involves easily accessible N,S‐acetals obtained from cost‐effective basic ketones and cysteamine as starting materials. This process ultimately leads to 1,4‐thiazines related to natural product and fused derivatives necessary for further QSAR study.

Site‐Selective Pd‐Catalysed Fujiwara‐Moritani type Reaction of N,S‐Heterocyclic Systems with Olefins

“…With chiral substrates functionalized at their C 4 ‐position either by an ester ( 2 r , R 1 =CO 2 Et) or an amide ( 2 s , R 1 =CONHBn) function obtained previously, [10] the C−H alkenylation worked well and led after 21 h to the expected products 3 r and 3 r in yields of 71% and 67%, respectively. In the latter case, 1 H NMR analysis of the crude showed also traces of a second product which corresponded to compound 3 t .…”

“…In the framework of our ongoing project dedicated to the development of new complex N,S ‐heterocyclic systems [6] with inhibitory activity on human farnesyltransferase (hFTase), [7] considered as anticancer target as well as for its high implication in Hutchinson‐Gilford progeria Syndrome (called also progeria), [8] our group recently reported the elaboration a series of bioactive 1,3‐thiazolone derivatives [9] . Quantitative Structure‐Activity Relationship (QSAR) studies necessary for this project initially led to 1,4‐thiazinones by exploring a innovative PIDA ((diacetoxyiodo)benzene)/I 2 ‐mediated domino approach starting from the corresponding substituted 1,3‐thiazolones in single‐step Morin rearrangement (Scheme 1, Path I ) [10] …”

“…Next, the required sulfoxides 3 a , 3 u and sulfones 7 a , 7 u were synthesized in one step starting from substrates 2 a , 2 u reported recently (Scheme 5). [10] These substrates were obtained, respectively, by sulfoxidation of 2 a , 2 u under optimal controlled conditions using NaIO 4 (1.4 eq. ) [17] in a mixture of MeOH/H 2 O in 9/1 ratio and their sulfonation using an excess of magnesium monoperoxyphthalate (MMPP, 2.3 eq.…”

Synthesis of Heterocycles from 2‐Acylbenzoic Acids

“…[41] The dehydration condensation reaction of 2-acylbenzoic acids and primary amines with two nucleophilic sites is a simple and efficient method to construct N-polycyclic compounds with isoindolinone skeletons. [42] In 2021, Xinming Xu et al disclosed an efficient and practical p-toluenesulfonic acid-catalyzed cascade cyclization reaction of 2-acylbenzoic acids with amines for the synthesis of diverse isoindoloisoquinoline and benzoindolizinoindole derivatives (Scheme 23). [43] A wide range of substrates with functional groups was well tolerated, affording lots of isoindoloisoquinolines and benzoindolizinoindoles in excellent yields.…”

Phenyliodine(III)diacetate (PIDA): Applications in Organic Synthesis

“…Particularly intriguing are the rare pyrrolo [1,4]thiazines, which can be represented with various degrees of biological relevance. Starting with N,S-acetals (74/76), an effective domino transformation using the PIDA/I 2 combination was developed by Daïch et al [27]. for Morin 1,4-thiazine compounds (75).…”