Double Nucleophilic Addition of Azide and Tetramethallyltin to α,β-Unsaturated Aldimines Promoted by Aluminum Chloride

Abstract

In the presence of AlCl3, a mixture of hydrogen azide and tetramethallyltin underwent 1,4- and subsequently 1,2-addition, respectively, with α,β-unsaturated aldimines to give 1,3-amino azides in good yields. The 1,3-amino azides thus obtained were readily converted into 1,3-diamines by reduction with LiAlH4.

Stereoselectivity in Nucleophilic Additions to 3-Azidoalkanals

“…Although nucleophilic additions to 3-azidoalkanals and 3-azidoalkanaldimines have been rarely reported, 1,3- anti -stereoselectivity in nucleophilic additions to other 3-heteroatom-substituted aldehydes is well precedented. Reetz’s half-chair model and Evans’s dipole−dipole interaction model are generally used to explain the observed selectivities in nucleophilic additions to aldehydes under chelation and non-chelation conditions, respectively (Scheme ).…”

One-Pot Synthesis of Lactams Using Domino Reactions: Combination of Schmidt Reaction with Sakurai and Aldol Reactions

“…Kihlberg proposed chelation of an azide nitrogen with an acetal oxygen via a Lewis acidic silicon atom and supported this idea with a 15 N NMR experiment . Shimizu proposed a chelated half-chair transition state to explain anti -1,3-stereoselectivities in nucleophilic addition to a 3-azidoimine. , Thus, intermediacy of chelate 39b could plausibly explain the observed anti -selectivity of our aldol reaction. It is unclear if such chelation could compensate for an unfavorable pseudodiaxial interaction between an α - hydrogen of the enolate reaction partner and the α-methylene group of the aldehyde in the boatlike transition state, which would instead favor alternative boatlike transition state 39c leading to minor aldol intermediate syn - 40 .…”

“…Kihlberg proposed chelation of an azide nitrogen with an acetal oxygen via a Lewis acidic silicon atom and supported this idea with 15 N NMR experiment 29. Shimizu proposed a chelated half-chair transition state to explain anti -1,3-stereoselectivities in nucleophilic addition to a 3-azidoimine 30,31. Thus, intermediacy of chelate 39b could plausibly explain the observed anti -selectivity of our aldol reaction.…”

Conjugated imines and iminium salts as versatile acceptors of nucleophiles

“…11 5. HN 3 as the nucleophile 16 Although there are several reports on 1,3-amino alcohols and 1,3-diols, limited examples are available for their 1,3-diamine analogues. 17 This is due in part to lack of general synthetic methodologies for 1,3-diamines.…”