Tetrahedron

Rh (II)-carbenoid mediated 2H-azirine ring-expansion as a convenient route to non-fused photo-and thermochromic 2H-1, 4-oxazines

…, AF Khlebnikov, VA Khlebnikov, SM Korneev

Index: Rostovskii, Nikolai V.; Novikov, Mikhail S.; Khlebnikov, Alexander F.; Khlebnikov, Vsevolod A.; Korneev, Sergei M. Tetrahedron, 2013 , vol. 69, # 21 p. 4292 - 4301

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Citation Number: 12

Abstract

The Rh2 (OAc) 4-catalyzed domino reaction of 2H-azirines with 2-acyl-2-diazoacetates provides a unique synthetic approach to non-fused 2H-1, 4-oxazines. The reaction proceeds via sequential formation of a rhodium carbenoid, an azirinium ylide, and a 1-acyl-1- (alkoxycarbonyl)-2-azabuta-1, 3-diene to give, after 1, 6-π-electrocyclization, a 2H-1, 4- oxazine derivative in good yield. The observed stereoselectivity of 2-azadiene formation is ...