Reaction of Dialumane Incorporating Bulky Eind Groups with Pyridines
Round 1
Reviewer 1 Report
This study represents some interesting results on the chemistry of aluminum hydrides. The possibility of the formation of stable Py adducts was shown. The novel structures were characterized by the means of NMR and XRD. The work was done on the high professional level.
However some minor details should be pointed out:
In the Scheme 1 (c) the arrow should be replaced by the equilibrium arrows, substances III and IV (1) should be removed from the right part of the Scheme. In the SI Figure S13 is 13C NMR, not 7Li. Lines 222-223: the reaction is not metathesis, because the oxidation numbers are changed. In Figure 3 it should be better to add the signatures of groups of atoms and possible intermediates. Scheme 5: the transformation of E’ into F or G into H is not understandable. May by it occur within one pyridine fragment? The exchange between pyridine protons and hydrides on Al in structures 2–4 could be sought using the EXSY method at different temperatures. I think this would greatly help in understanding the exchange processes in these systems.
Author Response
We very much appreciate several crucial comments for our chemistry.
Attached you will find the author's reply to the review report (Reviewer 1).
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The current submission describes the reaction of a bulky aryl aluminium dihydride compound (1) towards pyridine and 4-pyrrolidinopyridine, the former resulting in hydroalumination, but the latter not. The deuterated form of 1 was synthesised, and its reaction towards pyridine monitored to gain some mechanistic insight into this process. Overall the chemistry and analysis is clearly described, and the two novel compounds adequately analysed. DFT investigations are also included. There are only a small number of minor errors in the text that this reviewer noticed:
Line 111: delete 'of' at the beginning of the line.
Line 133: delete 'definitely'
Line 195: replace 'by a gentle' with 'extracted by gently'
Lines 220 and 224: delete the space after 'deuterio- '
This reviewers major comments on this manuscript regard the deuterium labelling experiment. It is certainly nice that the deuterium derivative of 1 (i.e. 1-d4) was synthesised. However, in its reaction with pyridine the 1H NMR spectra are not mentioned. I would imagine that a comparison of this 1H NMR, the corresponding 2H NMR, and 1H NMR spectra of 3 would give a good insight as to whether isomer F or H is formed in the reaction of 1-d4 with pyridine, through observing the Al-H(D) region and the Py-C-H(D) region.
Aside from these points, the manuscript is essentially ready for publication in Inorganics.
Author Response
Many thanks for very helpful comments concerning the improvements of our manuscript.
Attached you will find the author's reply to the review report (Reviewer 2).
Author Response File: Author Response.pdf
