The concept of borrowing hydrogen (also known as Hydrogen auto-transfer) is a useful concept which combines transfer hydrogenation with other reactions to produce more complex molecules, exemplified by the alkylation of amines with alcohols and the reaction of benzyl alcohol with acetophenone to give 1,3 diphenylpropanone. For the process chemist these processes seem to be very atom efficient and can be used. A recent review by Avelino Corma and colleagues in Valencia, Spain examines a wide range of processes, mostly alkylations of C and N substrates, and covers the literature up to about 2016, with 355 references.
Corma et al, Chem Rev 2018 DOI 10.1021/acs.chemrev.7b00340
