Boost 1.62's C++11 compiler checks fail when using gcc-5.3.0 provided by mingw

I have Windows 10 Pro running on a VirtualBox VM (hosted on Ubuntu 16.04).

I have installed the latest mingw

• mingw32-base version 2013072200
• mingw32-gcc-g++ version 5.3.0-3
• msys-base version 2013072200

I have downloaded boost 1.62.0 and am attempting to compile it.

I have opened the msys shell, and performed the following:

I have confirmed my g++ version:

$ g++ --version
g++.exe (GCC) 5.3.0
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

I have succssfully bootstrapped boost build:

$ ./bootstrap.sh
Building Boost.Build engine with toolset gcc... tools/build/src/engine/bin.ntx86/b2
Unicode/ICU support for Boost.Regex?... not found.
Generating Boost.Build configuration in project-config.jam...

Bootstrapping is done. To build, run:

    ./b2

To adjust configuration, edit 'project-config.jam'.
Further information:

   - Command line help:
     ./b2 --help

   - Getting started guide:
     http://ift.tt/WjxCdZ

   - Boost.Build documentation:
     http://ift.tt/2n3rvN5

However, when I try build the libraries, most of the C++11 feature checks fail:

$ ./b2 -j4
Performing configuration checks

    - 32-bit                   : yes
    - arm                      : no
    - mips1                    : no
    - power                    : no
    - sparc                    : no
    - x86                      : yes

Building the Boost C++ Libraries.


    - symlinks supported       : no
    - junctions supported      : yes
    - hardlinks supported      : yes
    - C++11 mutex              : no
    - Boost.Config Feature Check: cxx11_auto_declarations : no
    - Boost.Config Feature Check: cxx11_constexpr : no
    - Boost.Config Feature Check: cxx11_defaulted_functions : no
    - Boost.Config Feature Check: cxx11_final : yes
    - Boost.Config Feature Check: cxx11_hdr_tuple : no
    - Boost.Config Feature Check: cxx11_lambdas : no
    - Boost.Config Feature Check: cxx11_noexcept : no
    - Boost.Config Feature Check: cxx11_nullptr : no
    - Boost.Config Feature Check: cxx11_rvalue_references : no
    - Boost.Config Feature Check: cxx11_template_aliases : no
    - Boost.Config Feature Check: cxx11_thread_local : no
    - Boost.Config Feature Check: cxx11_variadic_templates : yes

What do I need to do for boost config to pick up that I am using a C++11 compliant compiler?