A Novel Synthetic Approach to Diaminoacetylenes: Structural Characterization and Reactivity of Aromatic and Aliphatic Ynediamines

Borabicyclo[3.2.0]heptadiene: A Fused Bicyclic Isomer of Borepin

“…The 1 HNMR spectrum of 2 exhibited three distinct chemical environments for the mesitylm ethyl groups, suggesting restricted rotationa round the BÀC(mesityl) bond and formation of an unsymmetrical structure. Closer analysiso f the complex 13 CNMR spectrum revealed two quaternary carbon atoms at 71 and 90 ppm, indicating the possible formation of ab icyclic structure. Clearly,t he NMR data was not consistent with either the formation of ab orepin or a7 -boranorbornadiene, products that have been observed by using less electron-rich alkynes.…”

Dimerisation of Dipiperidinoacetylene: Convenient Access to Tetraamino‐1,3‐Cyclobutadiene and Tetraamino‐1,2‐Cyclobutadiene Metal Complexes

“…The rather laborious nature of this and related protocols has prevented broad application in organic synthesis, whereas an interesting reactivity towards organotransition‐metal complexes was discovered . In 2010, our group established a novel synthetic approach that relies on a Fritsch–Buttenberg–Wiechell rearrangement upon lithiation of 2,2‐dibromo‐1,1‐ethylenediamines and provides convenient access to diaminoacetylenes such as 1,2‐dipiperidinoacetylene ( 1 ) . With 1 and related species in hand, several mono‐ and bimetallic transition‐metal complexes have been prepared, such as ruthenium(II) complex I , in which the long C−C bond indicates that the alkyne acts as a chelating four‐electron diaminodicarbene ligand (Figure ) .…”

Novel ynamide structural analogues and their synthetic transformations

“…Instead, indole 13 was formed via an intramolecular 1,5 C-H insertion of the vinylidene intermediate 12. 27 The successful synthesis of 1,2-dipiperidinoacetylene 10-b enabled studies of coordination chemistry on diaminoacetylenes through preparations of a series of structurally interesting metal complexes such as monometallic complex 14, homobimetallic complex 15, and heterobimetallic complex 16 (Scheme 3). 42 albeit the former used an internal yne-hydrazide, while the latter employed a terminal yne-hydrazide.…”

“…Very recently, preparations of structural analogues of ynamides have emerged as novel N-containing alkyne building blocks. [27][28][29][30][31][32][33][34][35][36] These preparations mainly are based on modified methods for ynamide synthesis [22][23][24][25][26] as described in Scheme 1. With the belief that these novel analogues will also become versatile synthons that will be tremendously useful to organic synthesis, especially in the arena of N-heterocycle constructions, we highlight herein syntheses and reactions of de novo ynamide analogues: diaminoacetylenes 2, ynimides 3, yne-imines 4, yne-hydrazides 5, amidinylynamides 6, and yne-sulfoximines 7 (Scheme 1).…”